aboutsummaryrefslogtreecommitdiff
path: root/src/main/java/org/traccar/protocol/HuabaoProtocolDecoder.java
blob: b1b065780bcfcd5a25281973476289fd97f0fb39 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
/*
 * Copyright 2015 - 2023 Anton Tananaev (anton@traccar.org)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.traccar.protocol;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import org.traccar.BaseProtocolDecoder;
import org.traccar.session.DeviceSession;
import org.traccar.NetworkMessage;
import org.traccar.Protocol;
import org.traccar.helper.BcdUtil;
import org.traccar.helper.BitUtil;
import org.traccar.helper.Checksum;
import org.traccar.helper.DateBuilder;
import org.traccar.helper.UnitsConverter;
import org.traccar.model.CellTower;
import org.traccar.model.Network;
import org.traccar.model.Position;

import java.net.SocketAddress;
import java.nio.charset.StandardCharsets;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
import java.util.TimeZone;

public class HuabaoProtocolDecoder extends BaseProtocolDecoder {

    public HuabaoProtocolDecoder(Protocol protocol) {
        super(protocol);
    }

    public static final int MSG_GENERAL_RESPONSE = 0x8001;
    public static final int MSG_GENERAL_RESPONSE_2 = 0x4401;
    public static final int MSG_HEARTBEAT = 0x0002;
    public static final int MSG_HEARTBEAT_2 = 0x0506;
    public static final int MSG_TERMINAL_REGISTER = 0x0100;
    public static final int MSG_TERMINAL_REGISTER_RESPONSE = 0x8100;
    public static final int MSG_TERMINAL_CONTROL = 0x8105;
    public static final int MSG_TERMINAL_AUTH = 0x0102;
    public static final int MSG_LOCATION_REPORT = 0x0200;
    public static final int MSG_LOCATION_BATCH_2 = 0x0210;
    public static final int MSG_ACCELERATION = 0x2070;
    public static final int MSG_LOCATION_REPORT_2 = 0x5501;
    public static final int MSG_LOCATION_REPORT_BLIND = 0x5502;
    public static final int MSG_LOCATION_BATCH = 0x0704;
    public static final int MSG_OIL_CONTROL = 0XA006;
    public static final int MSG_TIME_SYNC_REQUEST = 0x0109;
    public static final int MSG_TIME_SYNC_RESPONSE = 0x8109;
    public static final int MSG_PHOTO = 0x8888;
    public static final int MSG_TRANSPARENT = 0x0900;

    public static final int RESULT_SUCCESS = 0;

    public static ByteBuf formatMessage(int type, ByteBuf id, boolean shortIndex, ByteBuf data) {
        ByteBuf buf = Unpooled.buffer();
        buf.writeByte(0x7e);
        buf.writeShort(type);
        buf.writeShort(data.readableBytes());
        buf.writeBytes(id);
        if (shortIndex) {
            buf.writeByte(1);
        } else {
            buf.writeShort(0);
        }
        buf.writeBytes(data);
        data.release();
        buf.writeByte(Checksum.xor(buf.nioBuffer(1, buf.readableBytes() - 1)));
        buf.writeByte(0x7e);
        return buf;
    }

    private void sendGeneralResponse(
            Channel channel, SocketAddress remoteAddress, ByteBuf id, int type, int index) {
        if (channel != null) {
            ByteBuf response = Unpooled.buffer();
            response.writeShort(index);
            response.writeShort(type);
            response.writeByte(RESULT_SUCCESS);
            channel.writeAndFlush(new NetworkMessage(
                    formatMessage(MSG_GENERAL_RESPONSE, id, false, response), remoteAddress));
        }
    }

    private void sendGeneralResponse2(
            Channel channel, SocketAddress remoteAddress, ByteBuf id, int type) {
        if (channel != null) {
            ByteBuf response = Unpooled.buffer();
            response.writeShort(type);
            response.writeByte(RESULT_SUCCESS);
            channel.writeAndFlush(new NetworkMessage(
                    formatMessage(MSG_GENERAL_RESPONSE_2, id, true, response), remoteAddress));
        }
    }

    private String decodeAlarm(long value) {
        if (BitUtil.check(value, 0)) {
            return Position.ALARM_SOS;
        }
        if (BitUtil.check(value, 1)) {
            return Position.ALARM_OVERSPEED;
        }
        if (BitUtil.check(value, 5)) {
            return Position.ALARM_GPS_ANTENNA_CUT;
        }
        if (BitUtil.check(value, 4) || BitUtil.check(value, 9)
                || BitUtil.check(value, 10) || BitUtil.check(value, 11)) {
            return Position.ALARM_FAULT;
        }
        if (BitUtil.check(value, 7) || BitUtil.check(value, 18)) {
            return Position.ALARM_LOW_BATTERY;
        }
        if (BitUtil.check(value, 8)) {
            return Position.ALARM_POWER_OFF;
        }
        if (BitUtil.check(value, 15)) {
            return Position.ALARM_VIBRATION;
        }
        if (BitUtil.check(value, 16) || BitUtil.check(value, 17)) {
            return Position.ALARM_TAMPERING;
        }
        if (BitUtil.check(value, 20)) {
            return Position.ALARM_GEOFENCE;
        }
        if (BitUtil.check(value, 28)) {
            return Position.ALARM_MOVEMENT;
        }
        if (BitUtil.check(value, 29) || BitUtil.check(value, 30)) {
            return Position.ALARM_ACCIDENT;
        }
        return null;
    }

    private int readSignedWord(ByteBuf buf) {
        int value = buf.readUnsignedShort();
        return BitUtil.check(value, 15) ? -BitUtil.to(value, 15) : BitUtil.to(value, 15);
    }

    private Date readDate(ByteBuf buf, TimeZone timeZone) {
        DateBuilder dateBuilder = new DateBuilder(timeZone)
                .setYear(BcdUtil.readInteger(buf, 2))
                .setMonth(BcdUtil.readInteger(buf, 2))
                .setDay(BcdUtil.readInteger(buf, 2))
                .setHour(BcdUtil.readInteger(buf, 2))
                .setMinute(BcdUtil.readInteger(buf, 2))
                .setSecond(BcdUtil.readInteger(buf, 2));
        return dateBuilder.getDate();
    }

    private String decodeId(ByteBuf id) {
        String serial = ByteBufUtil.hexDump(id);
        if (serial.matches("[0-9]+")) {
            return serial;
        } else {
            long imei = id.getUnsignedShort(0);
            imei = (imei << 32) + id.getUnsignedInt(2);
            return String.valueOf(imei) + Checksum.luhn(imei);
        }
    }

    @Override
    protected Object decode(
            Channel channel, SocketAddress remoteAddress, Object msg) throws Exception {

        ByteBuf buf = (ByteBuf) msg;

        if (buf.getByte(buf.readerIndex()) == '(') {
            String sentence = buf.toString(StandardCharsets.US_ASCII);
            if (sentence.contains("BASE,2")) {
                DateFormat dateFormat = new SimpleDateFormat("yyyyMMddHHmmss");
                dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));
                String response = sentence.replace("TIME", dateFormat.format(new Date()));
                if (channel != null) {
                    channel.writeAndFlush(new NetworkMessage(
                            Unpooled.copiedBuffer(response, StandardCharsets.US_ASCII), remoteAddress));
                }
                return null;
            } else {
                return decodeResult(channel, remoteAddress, sentence);
            }
        }

        buf.readUnsignedByte(); // start marker
        int type = buf.readUnsignedShort();
        int attribute = buf.readUnsignedShort();
        ByteBuf id = buf.readSlice(6); // phone number
        int index;
        if (type == MSG_LOCATION_REPORT_2 || type == MSG_LOCATION_REPORT_BLIND) {
            index = buf.readUnsignedByte();
        } else {
            index = buf.readUnsignedShort();
        }

        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress, decodeId(id));
        if (deviceSession == null) {
            return null;
        }

        if (!deviceSession.contains(DeviceSession.KEY_TIMEZONE)) {
            deviceSession.set(DeviceSession.KEY_TIMEZONE, getTimeZone(deviceSession.getDeviceId(), "GMT+8"));
        }

        if (type == MSG_TERMINAL_REGISTER) {

            if (channel != null) {
                ByteBuf response = Unpooled.buffer();
                response.writeShort(index);
                response.writeByte(RESULT_SUCCESS);
                response.writeBytes(decodeId(id).getBytes(StandardCharsets.US_ASCII));
                channel.writeAndFlush(new NetworkMessage(
                        formatMessage(MSG_TERMINAL_REGISTER_RESPONSE, id, false, response), remoteAddress));
            }

        } else if (type == MSG_TERMINAL_AUTH || type == MSG_HEARTBEAT || type == MSG_HEARTBEAT_2 || type == MSG_PHOTO) {

            sendGeneralResponse(channel, remoteAddress, id, type, index);

        } else if (type == MSG_LOCATION_REPORT) {

            sendGeneralResponse(channel, remoteAddress, id, type, index);

            return decodeLocation(deviceSession, buf);

        } else if (type == MSG_LOCATION_REPORT_2 || type == MSG_LOCATION_REPORT_BLIND) {

            if (BitUtil.check(attribute, 15)) {
                sendGeneralResponse2(channel, remoteAddress, id, type);
            }

            return decodeLocation2(deviceSession, buf, type);

        } else if (type == MSG_LOCATION_BATCH || type == MSG_LOCATION_BATCH_2) {

            sendGeneralResponse(channel, remoteAddress, id, type, index);

            return decodeLocationBatch(deviceSession, buf, type);

        } else if (type == MSG_TIME_SYNC_REQUEST) {

            if (channel != null) {
                Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
                ByteBuf response = Unpooled.buffer();
                response.writeShort(calendar.get(Calendar.YEAR));
                response.writeByte(calendar.get(Calendar.MONTH) + 1);
                response.writeByte(calendar.get(Calendar.DAY_OF_MONTH));
                response.writeByte(calendar.get(Calendar.HOUR_OF_DAY));
                response.writeByte(calendar.get(Calendar.MINUTE));
                response.writeByte(calendar.get(Calendar.SECOND));
                channel.writeAndFlush(new NetworkMessage(
                        formatMessage(MSG_TERMINAL_REGISTER_RESPONSE, id, false, response), remoteAddress));
            }

        } else if (type == MSG_ACCELERATION) {

            Position position = new Position(getProtocolName());
            position.setDeviceId(deviceSession.getDeviceId());

            getLastLocation(position, null);

            StringBuilder data = new StringBuilder("[");
            while (buf.readableBytes() > 2) {
                buf.skipBytes(6); // time
                if (data.length() > 1) {
                    data.append(",");
                }
                data.append("[");
                data.append(readSignedWord(buf));
                data.append(",");
                data.append(readSignedWord(buf));
                data.append(",");
                data.append(readSignedWord(buf));
                data.append("]");
            }
            data.append("]");

            position.set(Position.KEY_G_SENSOR, data.toString());

            return position;

        } else if (type == MSG_TRANSPARENT) {

            sendGeneralResponse(channel, remoteAddress, id, type, index);

            return decodeTransparent(deviceSession, buf);

        }

        return null;
    }

    private Position decodeResult(Channel channel, SocketAddress remoteAddress, String sentence) {
        DeviceSession deviceSession = getDeviceSession(channel, remoteAddress);
        if (deviceSession != null) {
            Position position = new Position(getProtocolName());
            position.setDeviceId(deviceSession.getDeviceId());
            getLastLocation(position, null);
            position.set(Position.KEY_RESULT, sentence);
            return position;
        }
        return null;
    }

    private void decodeExtension(Position position, ByteBuf buf, int endIndex) {
        while (buf.readerIndex() < endIndex) {
            int type = buf.readUnsignedByte();
            int length = buf.readUnsignedByte();
            switch (type) {
                case 0x01:
                    position.set(Position.KEY_ODOMETER, buf.readUnsignedInt() * 100L);
                    break;
                case 0x02:
                    position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedShort() * 0.1);
                    break;
                case 0x03:
                    position.set(Position.KEY_OBD_SPEED, buf.readUnsignedShort() * 0.1);
                    break;
                case 0x56:
                    buf.readUnsignedByte(); // power level
                    position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte());
                    break;
                case 0x61:
                    position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.01);
                    break;
                case 0x69:
                    position.set(Position.KEY_BATTERY, buf.readUnsignedShort() * 0.01);
                    break;
                case 0x80:
                    position.set(Position.KEY_OBD_SPEED, buf.readUnsignedByte());
                    break;
                case 0x81:
                    position.set(Position.KEY_RPM, buf.readUnsignedShort());
                    break;
                case 0x82:
                    position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.1);
                    break;
                case 0x83:
                    position.set(Position.KEY_ENGINE_LOAD, buf.readUnsignedByte());
                    break;
                case 0x84:
                    position.set(Position.KEY_COOLANT_TEMP, buf.readUnsignedByte() - 40);
                    break;
                case 0x85:
                    position.set(Position.KEY_FUEL_CONSUMPTION, buf.readUnsignedShort());
                    break;
                case 0x86:
                    position.set("intakeTemp", buf.readUnsignedByte() - 40);
                    break;
                case 0x87:
                    position.set("intakeFlow", buf.readUnsignedShort());
                    break;
                case 0x88:
                    position.set("intakePressure", buf.readUnsignedByte());
                    break;
                case 0x89:
                    position.set(Position.KEY_THROTTLE, buf.readUnsignedByte());
                    break;
                case 0x8B:
                    position.set(Position.KEY_VIN, buf.readCharSequence(17, StandardCharsets.US_ASCII).toString());
                    break;
                case 0x8C:
                    position.set(Position.KEY_OBD_ODOMETER, buf.readUnsignedInt() * 100L);
                    break;
                case 0x8D:
                    position.set(Position.KEY_ODOMETER_TRIP, buf.readUnsignedShort() * 1000L);
                    break;
                case 0x8E:
                    position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedByte());
                    break;
                case 0xA0:
                    String codes = buf.readCharSequence(length, StandardCharsets.US_ASCII).toString();
                    position.set(Position.KEY_DTCS, codes.replace(',', ' '));
                    break;
                case 0xCC:
                    position.set(Position.KEY_ICCID, buf.readCharSequence(20, StandardCharsets.US_ASCII).toString());
                    break;
                default:
                    buf.skipBytes(length);
                    break;
            }
        }
    }

    private void decodeCoordinates(Position position, ByteBuf buf) {

        int status = buf.readInt();

        position.set(Position.KEY_IGNITION, BitUtil.check(status, 0));
        position.set(Position.KEY_MOTION, BitUtil.check(status, 4));
        position.set(Position.KEY_BLOCKED, BitUtil.check(status, 10));
        position.set(Position.KEY_CHARGE, BitUtil.check(status, 26));

        position.setValid(BitUtil.check(status, 1));

        double lat = buf.readUnsignedInt() * 0.000001;
        double lon = buf.readUnsignedInt() * 0.000001;

        if (BitUtil.check(status, 2)) {
            position.setLatitude(-lat);
        } else {
            position.setLatitude(lat);
        }

        if (BitUtil.check(status, 3)) {
            position.setLongitude(-lon);
        } else {
            position.setLongitude(lon);
        }
    }

    private double decodeCustomDouble(ByteBuf buf) {
        int b1 = buf.readByte();
        int b2 = buf.readUnsignedByte();
        int sign = b1 != 0 ? b1 / Math.abs(b1) : 1;
        return sign * (Math.abs(b1) + b2 / 255.0);
    }

    private Position decodeLocation(DeviceSession deviceSession, ByteBuf buf) {

        Position position = new Position(getProtocolName());
        position.setDeviceId(deviceSession.getDeviceId());

        position.set(Position.KEY_ALARM, decodeAlarm(buf.readUnsignedInt()));

        decodeCoordinates(position, buf);

        position.setAltitude(buf.readShort());
        position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShort() * 0.1));
        position.setCourse(buf.readUnsignedShort());
        position.setTime(readDate(buf, deviceSession.get(DeviceSession.KEY_TIMEZONE)));

        if (buf.readableBytes() == 20) {

            buf.skipBytes(4); // remaining battery and mileage
            position.set(Position.KEY_ODOMETER, buf.readUnsignedInt() * 1000);
            position.set(Position.KEY_BATTERY, buf.readUnsignedShort() * 0.1);
            buf.readUnsignedInt(); // area id
            position.set(Position.KEY_RSSI, buf.readUnsignedByte());
            buf.skipBytes(3); // reserved

            return position;

        }

        while (buf.readableBytes() > 2) {

            int subtype = buf.readUnsignedByte();
            int length = buf.readUnsignedByte();
            int endIndex = buf.readerIndex() + length;
            String stringValue;
            switch (subtype) {
                case 0x01:
                    position.set(Position.KEY_ODOMETER, buf.readUnsignedInt() * 100);
                    break;
                case 0x02:
                    position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedShort() * 0.1);
                    break;
                case 0x25:
                    position.set(Position.KEY_INPUT, buf.readUnsignedInt());
                    break;
                case 0x2b:
                    position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort());
                    position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShort());
                    break;
                case 0x30:
                    position.set(Position.KEY_RSSI, buf.readUnsignedByte());
                    break;
                case 0x31:
                    position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
                    break;
                case 0x33:
                    stringValue = buf.readCharSequence(length, StandardCharsets.US_ASCII).toString();
                    if (stringValue.startsWith("*M00")) {
                        String lockStatus = stringValue.substring(8, 8 + 7);
                        position.set(Position.KEY_BATTERY, Integer.parseInt(lockStatus.substring(2, 5)) * 0.01);
                    }
                    break;
                case 0x51:
                    if (length == 16) {
                        for (int i = 1; i <= 8; i++) {
                            position.set(Position.PREFIX_TEMP + i, buf.readShort());
                        }
                    }
                    break;
                case 0x56:
                    position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte() * 10);
                    buf.readUnsignedByte(); // reserved
                    break;
                case 0x57:
                    int alarm = buf.readUnsignedShort();
                    position.set(Position.KEY_ALARM, BitUtil.check(alarm, 8) ? Position.ALARM_ACCELERATION : null);
                    position.set(Position.KEY_ALARM, BitUtil.check(alarm, 9) ? Position.ALARM_BRAKING : null);
                    position.set(Position.KEY_ALARM, BitUtil.check(alarm, 10) ? Position.ALARM_CORNERING : null);
                    buf.readUnsignedShort(); // external switch state
                    buf.skipBytes(4); // reserved
                    break;
                case 0x60:
                    int event = buf.readUnsignedShort();
                    position.set(Position.KEY_EVENT, event);
                    if (event >= 0x0061 && event <= 0x0066) {
                        buf.skipBytes(6); // lock id
                        stringValue = buf.readCharSequence(8, StandardCharsets.US_ASCII).toString();
                        position.set(Position.KEY_DRIVER_UNIQUE_ID, stringValue);
                    }
                    break;
                case 0x63:
                    for (int i = 1; i <= length / 11; i++) {
                        position.set("lock" + i + "Id", ByteBufUtil.hexDump(buf.readSlice(6)));
                        position.set("lock" + i + "Battery", buf.readUnsignedShort() * 0.001);
                        position.set("lock" + i + "Seal", buf.readUnsignedByte() == 0x31);
                        buf.readUnsignedByte(); // physical state
                        buf.readUnsignedByte(); // rssi
                    }
                    break;
                case 0x64:
                    buf.readUnsignedInt(); // alarm serial number
                    buf.readUnsignedByte(); // alarm status
                    position.set("adasAlarm", buf.readUnsignedByte());
                    break;
                case 0x65:
                    buf.readUnsignedInt(); // alarm serial number
                    buf.readUnsignedByte(); // alarm status
                    position.set("dmsAlarm", buf.readUnsignedByte());
                    break;
                case 0x70:
                    buf.readUnsignedInt(); // alarm serial number
                    buf.readUnsignedByte(); // alarm status
                    switch (buf.readUnsignedByte()) {
                        case 0x01:
                            position.set(Position.KEY_ALARM, Position.ALARM_ACCELERATION);
                            break;
                        case 0x02:
                            position.set(Position.KEY_ALARM, Position.ALARM_BRAKING);
                            break;
                        case 0x03:
                            position.set(Position.KEY_ALARM, Position.ALARM_CORNERING);
                            break;
                        case 0x16:
                            position.set(Position.KEY_ALARM, Position.ALARM_ACCIDENT);
                            break;
                        default:
                            break;
                    }
                    break;
                case 0x69:
                    position.set(Position.KEY_BATTERY, buf.readUnsignedShort() * 0.01);
                    break;
                case 0x80:
                    buf.readUnsignedByte(); // content
                    endIndex = buf.writerIndex() - 2;
                    decodeExtension(position, buf, endIndex);
                    break;
                case 0x91:
                    position.set(Position.KEY_BATTERY, buf.readUnsignedShort() * 0.1);
                    position.set(Position.KEY_RPM, buf.readUnsignedShort());
                    position.set(Position.KEY_OBD_SPEED, buf.readUnsignedByte());
                    position.set(Position.KEY_THROTTLE, buf.readUnsignedByte() * 100 / 255);
                    position.set(Position.KEY_ENGINE_LOAD, buf.readUnsignedByte() * 100 / 255);
                    position.set(Position.KEY_COOLANT_TEMP, buf.readUnsignedByte() - 40);
                    buf.readUnsignedShort();
                    position.set(Position.KEY_FUEL_CONSUMPTION, buf.readUnsignedShort() * 0.01);
                    buf.readUnsignedShort();
                    buf.readUnsignedInt();
                    buf.readUnsignedShort();
                    position.set(Position.KEY_FUEL_USED, buf.readUnsignedShort() * 0.01);
                    break;
                case 0x94:
                    if (length > 0) {
                        stringValue = buf.readCharSequence(length, StandardCharsets.US_ASCII).toString();
                        position.set(Position.KEY_VIN, stringValue);
                    }
                    break;
                case 0xA7:
                    position.set(Position.PREFIX_ADC + 1, buf.readUnsignedShort());
                    position.set(Position.PREFIX_ADC + 2, buf.readUnsignedShort());
                    break;
                case 0xAC:
                    position.set(Position.KEY_ODOMETER, buf.readUnsignedInt());
                    break;
                case 0xBC:
                    stringValue = buf.readCharSequence(length, StandardCharsets.US_ASCII).toString();
                    position.set("driver", stringValue.trim());
                    break;
                case 0xBD:
                    stringValue = buf.readCharSequence(length, StandardCharsets.US_ASCII).toString();
                    position.set(Position.KEY_DRIVER_UNIQUE_ID, stringValue);
                    break;
                case 0xD0:
                    long userStatus = buf.readUnsignedInt();
                    if (BitUtil.check(userStatus, 3)) {
                        position.set(Position.KEY_ALARM, Position.ALARM_VIBRATION);
                    }
                    break;
                case 0xD3:
                    position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.1);
                    break;
                case 0xD4:
                case 0xE1:
                    if (length == 1) {
                        position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte());
                    } else {
                        position.set(Position.KEY_DRIVER_UNIQUE_ID, String.valueOf(buf.readUnsignedInt()));
                    }
                    break;
                case 0xD5:
                    if (length == 2) {
                        position.set(Position.KEY_BATTERY, buf.readUnsignedShort() * 0.01);
                    } else {
                        int count = buf.readUnsignedByte();
                        for (int i = 1; i <= count; i++) {
                            position.set("lock" + i + "Id", ByteBufUtil.hexDump(buf.readSlice(5)));
                            position.set("lock" + i + "Card", ByteBufUtil.hexDump(buf.readSlice(5)));
                            position.set("lock" + i + "Battery", buf.readUnsignedByte());
                            int status = buf.readUnsignedShort();
                            position.set("lock" + i + "Locked", !BitUtil.check(status, 5));
                        }
                    }
                    break;
                case 0xDA:
                    buf.readUnsignedShort(); // string cut count
                    int deviceStatus = buf.readUnsignedByte();
                    position.set("string", BitUtil.check(deviceStatus, 0));
                    position.set(Position.KEY_MOTION, BitUtil.check(deviceStatus, 2));
                    position.set("cover", BitUtil.check(deviceStatus, 3));
                    break;
                case 0xE2:
                    position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedInt() * 0.1);
                    break;
                case 0xE6:
                    while (buf.readerIndex() < endIndex) {
                        int sensorIndex = buf.readUnsignedByte();
                        buf.skipBytes(6); // mac
                        position.set(Position.PREFIX_TEMP + sensorIndex, decodeCustomDouble(buf));
                        position.set("humidity" + sensorIndex, decodeCustomDouble(buf));
                    }
                    break;
                case 0xEB:
                    if (buf.getUnsignedShort(buf.readerIndex()) > 200) {
                        Network network = new Network();
                        int mcc = buf.readUnsignedShort();
                        int mnc = buf.readUnsignedByte();
                        while (buf.readerIndex() < endIndex) {
                            network.addCellTower(CellTower.from(
                                    mcc, mnc, buf.readUnsignedShort(), buf.readUnsignedShort(),
                                    buf.readUnsignedByte()));
                        }
                        position.setNetwork(network);
                    } else {
                        while (buf.readerIndex() < endIndex) {
                            int extendedLength = buf.readUnsignedShort();
                            int extendedType = buf.readUnsignedShort();
                            switch (extendedType) {
                                case 0x0001:
                                    position.set("fuel1", buf.readUnsignedShort() * 0.1);
                                    buf.readUnsignedByte(); // unused
                                    break;
                                case 0x0023:
                                    position.set("fuel2", Double.parseDouble(
                                            buf.readCharSequence(6, StandardCharsets.US_ASCII).toString()));
                                    break;
                                case 0x00B2:
                                    position.set(Position.KEY_ICCID, ByteBufUtil.hexDump(
                                            buf.readSlice(10)).replaceAll("f", ""));
                                    break;
                                case 0x00CE:
                                    position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.01);
                                    break;
                                case 0x00D8:
                                    Network network = new Network();
                                    network.addCellTower(CellTower.from(
                                            buf.readUnsignedShort(), buf.readUnsignedByte(),
                                            buf.readUnsignedShort(), buf.readUnsignedInt()));
                                    position.setNetwork(network);
                                    break;
                                case 0x00A8:
                                case 0x00E1:
                                    position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte());
                                    break;
                                default:
                                    buf.skipBytes(extendedLength - 2);
                                    break;
                            }
                        }
                    }
                    break;
                case 0xED:
                    stringValue = buf.readCharSequence(length, StandardCharsets.US_ASCII).toString();
                    position.set(Position.KEY_CARD, stringValue.trim());
                    break;
                case 0xEE:
                    position.set(Position.KEY_RSSI, buf.readUnsignedByte());
                    position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.001);
                    position.set(Position.KEY_BATTERY, buf.readUnsignedShort() * 0.001);
                    position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
                    break;
                case 0xF1:
                    position.set(Position.KEY_POWER, buf.readUnsignedInt() * 0.001);
                    break;
                case 0xF3:
                    while (buf.readerIndex() < endIndex) {
                        int extendedType = buf.readUnsignedShort();
                        int extendedLength = buf.readUnsignedByte();
                        switch (extendedType) {
                            case 0x0002:
                                position.set(Position.KEY_OBD_SPEED, buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0003:
                                position.set(Position.KEY_RPM, buf.readUnsignedShort());
                                break;
                            case 0x0004:
                                position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.001);
                                break;
                            case 0x0005:
                                position.set(Position.KEY_OBD_ODOMETER, buf.readUnsignedInt() * 100);
                                break;
                            case 0x0007:
                                position.set(Position.KEY_FUEL_CONSUMPTION, buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0008:
                                position.set(Position.KEY_ENGINE_LOAD, buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0009:
                                position.set(Position.KEY_COOLANT_TEMP, buf.readUnsignedShort() - 40);
                                break;
                            case 0x000B:
                                position.set("intakePressure", buf.readUnsignedShort());
                                break;
                            case 0x000C:
                                position.set("intakeTemp", buf.readUnsignedShort() - 40);
                                break;
                            case 0x000D:
                                position.set("intakeFlow", buf.readUnsignedShort());
                                break;
                            case 0x000E:
                                position.set(Position.KEY_THROTTLE, buf.readUnsignedShort() * 100 / 255);
                                break;
                            case 0x0050:
                                position.set(Position.KEY_VIN, buf.readSlice(17).toString(StandardCharsets.US_ASCII));
                                break;
                            case 0x0100:
                                position.set(Position.KEY_ODOMETER_TRIP, buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0102:
                                position.set("tripFuel", buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0112:
                                position.set("hardAccelerationCount", buf.readUnsignedShort());
                                break;
                            case 0x0113:
                                position.set("hardDecelerationCount", buf.readUnsignedShort());
                                break;
                            case 0x0114:
                                position.set("hardCorneringCount", buf.readUnsignedShort());
                                break;
                            default:
                                buf.skipBytes(extendedLength);
                                break;
                        }
                    }
                    break;
                case 0xF7:
                    position.set(Position.KEY_BATTERY, buf.readUnsignedInt() * 0.001);
                    if (length >= 5) {
                        short batteryStatus = buf.readUnsignedByte();
                        switch (batteryStatus) {
                            case 1:
                                position.set(Position.KEY_CHARGE, false);
                                break;
                            case 2:
                            case 3:
                                position.set(Position.KEY_CHARGE, true);
                            default:
                        }
                    }
                    if (length >= 6) {
                        position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte());
                    }
                    break;
                case 0xFE:
                    if (length == 1) {
                        position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte());
                    } else if (length == 2) {
                        position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.1);
                    } else {
                        int mark = buf.readUnsignedByte();
                        if (mark == 0x7C) {
                            while (buf.readerIndex() < endIndex) {
                                int extendedType = buf.readUnsignedByte();
                                int extendedLength = buf.readUnsignedByte();
                                switch (extendedType) {
                                    case 0x01:
                                        long alarms = buf.readUnsignedInt();
                                        if (BitUtil.check(alarms, 0)) {
                                            position.set(Position.KEY_ALARM, Position.ALARM_ACCELERATION);
                                        }
                                        if (BitUtil.check(alarms, 1)) {
                                            position.set(Position.KEY_ALARM, Position.ALARM_BRAKING);
                                        }
                                        if (BitUtil.check(alarms, 2)) {
                                            position.set(Position.KEY_ALARM, Position.ALARM_CORNERING);
                                        }
                                        if (BitUtil.check(alarms, 3)) {
                                            position.set(Position.KEY_ALARM, Position.ALARM_ACCIDENT);
                                        }
                                        if (BitUtil.check(alarms, 4)) {
                                            position.set(Position.KEY_ALARM, Position.ALARM_TAMPERING);
                                        }
                                        break;
                                    default:
                                        buf.skipBytes(extendedLength);
                                        break;
                                }
                            }
                        }
                        position.set(Position.KEY_BATTERY_LEVEL, buf.readUnsignedByte());
                    }
                    break;
                default:
                    break;
            }
            buf.readerIndex(endIndex);
        }

        return position;
    }

    private Position decodeLocation2(DeviceSession deviceSession, ByteBuf buf, int type) {

        Position position = new Position(getProtocolName());
        position.setDeviceId(deviceSession.getDeviceId());

        Jt600ProtocolDecoder.decodeBinaryLocation(buf, position);
        position.setValid(type != MSG_LOCATION_REPORT_BLIND);

        position.set(Position.KEY_RSSI, buf.readUnsignedByte());
        position.set(Position.KEY_SATELLITES, buf.readUnsignedByte());
        position.set(Position.KEY_ODOMETER, buf.readUnsignedInt() * 1000L);

        int battery = buf.readUnsignedByte();
        if (battery <= 100) {
            position.set(Position.KEY_BATTERY_LEVEL, battery);
        } else if (battery == 0xAA || battery == 0xAB) {
            position.set(Position.KEY_CHARGE, true);
        }

        long cid = buf.readUnsignedInt();
        int lac = buf.readUnsignedShort();
        if (cid > 0 && lac > 0) {
            position.setNetwork(new Network(CellTower.fromCidLac(getConfig(), cid, lac)));
        }

        int product = buf.readUnsignedByte();
        int status = buf.readUnsignedShort();
        int alarm = buf.readUnsignedShort();

        if (product == 1 || product == 2) {
            if (BitUtil.check(alarm, 0)) {
                position.set(Position.KEY_ALARM, Position.ALARM_LOW_POWER);
            }
        } else if (product == 3) {
            position.set(Position.KEY_BLOCKED, BitUtil.check(status, 5));
            if (BitUtil.check(alarm, 0)) {
                position.set(Position.KEY_ALARM, Position.ALARM_OVERSPEED);
            }
            if (BitUtil.check(alarm, 1)) {
                position.set(Position.KEY_ALARM, Position.ALARM_LOW_POWER);
            }
            if (BitUtil.check(alarm, 2)) {
                position.set(Position.KEY_ALARM, Position.ALARM_VIBRATION);
            }
            if (BitUtil.check(alarm, 3)) {
                position.set(Position.KEY_ALARM, Position.ALARM_LOW_BATTERY);
            }
            if (BitUtil.check(alarm, 5)) {
                position.set(Position.KEY_ALARM, Position.ALARM_GEOFENCE_ENTER);
            }
            if (BitUtil.check(alarm, 6)) {
                position.set(Position.KEY_ALARM, Position.ALARM_GEOFENCE_EXIT);
            }
        }

        position.set(Position.KEY_STATUS, status);

        while (buf.readableBytes() > 2) {
            int id = buf.readUnsignedByte();
            int length = buf.readUnsignedByte();
            switch (id) {
                case 0x02:
                    position.setAltitude(buf.readShort());
                    break;
                case 0x10:
                    position.set("wakeSource", buf.readUnsignedByte());
                    break;
                case 0x0A:
                    if (length == 3) {
                        buf.readUnsignedShort(); // mcc
                        buf.readUnsignedByte(); // mnc
                    } else {
                        buf.skipBytes(length);
                    }
                    break;
                case 0x0B:
                    position.set("lockCommand", buf.readUnsignedByte());
                    if (length >= 5 && length <= 6) {
                        position.set("lockCard", buf.readUnsignedInt());
                    } else if (length >= 7) {
                        position.set("lockPassword", buf.readCharSequence(6, StandardCharsets.US_ASCII).toString());
                    }
                    if (length % 2 == 0) {
                        position.set("unlockResult", buf.readUnsignedByte());
                    }
                    break;
                case 0x0C:
                    int x = buf.readUnsignedShort();
                    if (x > 0x8000) {
                        x -= 0x10000;
                    }
                    int y = buf.readUnsignedShort();
                    if (y > 0x8000) {
                        y -= 0x10000;
                    }
                    int z = buf.readUnsignedShort();
                    if (z > 0x8000) {
                        z -= 0x10000;
                    }
                    position.set("tilt", String.format("[%d,%d,%d]", x, y, z));
                    break;
                case 0xFC:
                    position.set(Position.KEY_GEOFENCE, buf.readUnsignedByte());
                    break;
                default:
                    buf.skipBytes(length);
                    break;
            }
        }

        return position;
    }

    private List<Position> decodeLocationBatch(DeviceSession deviceSession, ByteBuf buf, int type) {

        List<Position> positions = new LinkedList<>();

        int locationType = 0;
        if (type == MSG_LOCATION_BATCH) {
            buf.readUnsignedShort(); // count
            locationType = buf.readUnsignedByte();
        }

        while (buf.readableBytes() > 2) {
            int length = type == MSG_LOCATION_BATCH_2 ? buf.readUnsignedByte() : buf.readUnsignedShort();
            ByteBuf fragment = buf.readSlice(length);
            Position position = decodeLocation(deviceSession, fragment);
            if (locationType > 0) {
                position.set(Position.KEY_ARCHIVE, true);
            }
            positions.add(position);
        }

        return positions;
    }

    private Position decodeTransparent(DeviceSession deviceSession, ByteBuf buf) {

        int type = buf.readUnsignedByte();

        if (type == 0xF0) {

            Position position = new Position(getProtocolName());
            position.setDeviceId(deviceSession.getDeviceId());

            Date time = readDate(buf, deviceSession.get(DeviceSession.KEY_TIMEZONE));

            if (buf.readUnsignedByte() > 0) {
                position.set(Position.KEY_ARCHIVE, true);
            }

            buf.readUnsignedByte(); // vehicle type

            int count;
            int subtype = buf.readUnsignedByte();
            switch (subtype) {
                case 0x01:
                    count = buf.readUnsignedByte();
                    for (int i = 0; i < count; i++) {
                        int id = buf.readUnsignedShort();
                        int length = buf.readUnsignedByte();
                        switch (id) {
                            case 0x0102:
                            case 0x0528:
                            case 0x0546:
                                position.set(Position.KEY_ODOMETER, buf.readUnsignedInt() * 100);
                                break;
                            case 0x0103:
                                position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedInt() * 0.01);
                                break;
                            case 0x0111:
                                position.set("fuelTemp", buf.readUnsignedByte() - 40);
                                break;
                            case 0x012E:
                                position.set("oilLevel", buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x052A:
                                position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedShort() * 0.01);
                                break;
                            case 0x0105:
                            case 0x052C:
                                position.set(Position.KEY_FUEL_USED, buf.readUnsignedInt() * 0.01);
                                break;
                            case 0x014A:
                            case 0x0537:
                            case 0x0538:
                            case 0x0539:
                                position.set(Position.KEY_FUEL_CONSUMPTION, buf.readUnsignedShort() * 0.01);
                                break;
                            case 0x052B:
                                position.set(Position.KEY_FUEL_LEVEL, buf.readUnsignedByte());
                                break;
                            case 0x052D:
                                position.set(Position.KEY_COOLANT_TEMP, buf.readUnsignedByte() - 40);
                                break;
                            case 0x052E:
                                position.set("airTemp", buf.readUnsignedByte() - 40);
                                break;
                            case 0x0530:
                                position.set(Position.KEY_POWER, buf.readUnsignedShort() * 0.001);
                                break;
                            case 0x0535:
                                position.set(Position.KEY_OBD_SPEED, buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0536:
                                position.set(Position.KEY_RPM, buf.readUnsignedShort());
                                break;
                            case 0x053D:
                                position.set("intakePressure", buf.readUnsignedShort() * 0.1);
                                break;
                            case 0x0544:
                                position.set("liquidLevel", buf.readUnsignedByte());
                                break;
                            case 0x0547:
                            case 0x0548:
                                position.set(Position.KEY_THROTTLE, buf.readUnsignedByte());
                                break;
                            default:
                                switch (length) {
                                    case 1:
                                        position.set(Position.PREFIX_IO + id, buf.readUnsignedByte());
                                        break;
                                    case 2:
                                        position.set(Position.PREFIX_IO + id, buf.readUnsignedShort());
                                        break;
                                    case 4:
                                        position.set(Position.PREFIX_IO + id, buf.readUnsignedInt());
                                        break;
                                    default:
                                        buf.skipBytes(length);
                                        break;
                                }
                                break;
                        }
                    }
                    getLastLocation(position, time);
                    decodeCoordinates(position, buf);
                    position.setTime(time);
                    break;
                case 0x02:
                    List<String> codes = new LinkedList<>();
                    count = buf.readUnsignedShort();
                    for (int i = 0; i < count; i++) {
                        buf.readUnsignedInt(); // system id
                        int codeCount = buf.readUnsignedShort();
                        for (int j = 0; j < codeCount; j++) {
                            buf.readUnsignedInt(); // dtc
                            buf.readUnsignedInt(); // status
                            codes.add(buf.readCharSequence(
                                    buf.readUnsignedShort(), StandardCharsets.US_ASCII).toString().trim());
                        }
                    }
                    position.set(Position.KEY_DTCS, String.join(" ", codes));
                    getLastLocation(position, time);
                    decodeCoordinates(position, buf);
                    position.setTime(time);
                    break;
                case 0x03:
                    count = buf.readUnsignedByte();
                    for (int i = 0; i < count; i++) {
                        int id = buf.readUnsignedByte();
                        int length = buf.readUnsignedByte();
                        switch (id) {
                            case 0x01:
                                position.set(Position.KEY_ALARM, Position.ALARM_POWER_RESTORED);
                                break;
                            case 0x02:
                                position.set(Position.KEY_ALARM, Position.ALARM_POWER_CUT);
                                break;
                            case 0x1A:
                                position.set(Position.KEY_ALARM, Position.ALARM_ACCELERATION);
                                break;
                            case 0x1B:
                                position.set(Position.KEY_ALARM, Position.ALARM_BRAKING);
                                break;
                            case 0x1C:
                                position.set(Position.KEY_ALARM, Position.ALARM_CORNERING);
                                break;
                            case 0x1D:
                            case 0x1E:
                            case 0x1F:
                                position.set(Position.KEY_ALARM, Position.ALARM_LANE_CHANGE);
                                break;
                            case 0x23:
                                position.set(Position.KEY_ALARM, Position.ALARM_FATIGUE_DRIVING);
                                break;
                            case 0x26:
                            case 0x27:
                            case 0x28:
                                position.set(Position.KEY_ALARM, Position.ALARM_ACCIDENT);
                                break;
                            case 0x31:
                            case 0x32:
                                position.set(Position.KEY_ALARM, Position.ALARM_DOOR);
                                break;
                            default:
                                break;
                        }
                        buf.skipBytes(length);
                    }
                    getLastLocation(position, time);
                    decodeCoordinates(position, buf);
                    position.setTime(time);
                    break;
                case 0x0B:
                    if (buf.readUnsignedByte() > 0) {
                        position.set(Position.KEY_VIN, buf.readCharSequence(17, StandardCharsets.US_ASCII).toString());
                    }
                    getLastLocation(position, time);
                    break;
                case 0x15:
                    int event = buf.readInt();
                    switch (event) {
                        case 51:
                            position.set(Position.KEY_ALARM, Position.ALARM_ACCELERATION);
                            break;
                        case 52:
                            position.set(Position.KEY_ALARM, Position.ALARM_BRAKING);
                            break;
                        case 53:
                            position.set(Position.KEY_ALARM, Position.ALARM_CORNERING);
                            break;
                        case 54:
                            position.set(Position.KEY_ALARM, Position.ALARM_LANE_CHANGE);
                            break;
                        case 56:
                            position.set(Position.KEY_ALARM, Position.ALARM_ACCIDENT);
                            break;
                        default:
                            position.set(Position.KEY_EVENT, event);
                            break;
                    }
                    getLastLocation(position, time);
                    break;
                default:
                    return null;
            }

            return position;

        } else if (type == 0xFF) {

            Position position = new Position(getProtocolName());
            position.setDeviceId(deviceSession.getDeviceId());

            position.setValid(true);
            position.setTime(readDate(buf, deviceSession.get(DeviceSession.KEY_TIMEZONE)));
            position.setLatitude(buf.readInt() * 0.000001);
            position.setLongitude(buf.readInt() * 0.000001);
            position.setAltitude(buf.readShort());
            position.setSpeed(UnitsConverter.knotsFromKph(buf.readUnsignedShort() * 0.1));
            position.setCourse(buf.readUnsignedShort());

            // TODO more positions and g sensor data

            return position;

        }

        return null;
    }

}