UBX

u-blox binary receiver configuration, acknowledgements, monitoring, navigation results, and raw navigation words.

Connect the parser

using Asv.Gnss;
using Asv.IO;

var protocol = Protocol.Create(builder =>
{
    builder.Protocols.RegisterUbxProtocol();
});

The stream parser is UbxMessageParser and its message model is UbxMessageBase. See Quick Start for router, port, and subscription setup. Registration selects decoders; the receiver must already be configured to emit the required data.

Legacy model compatibility

RegisterUbxProtocol preserves the ACK, CFG, INF, MON, NAV, and RXM model types below. It also recognizes additional class/ID pairs from the X20 HPG 2.11 profile, using typed X20 models for IDs without a registered legacy model. A custom model registered through its configure callback keeps priority. UBX uses sync bytes B5 62; message identity combines class and message ID into a ushort.

The configure callback sees both the legacy and added X20 IDs. Its Remove and Clear operations are honored; payload selection does not add removed messages back.

Use RegisterUbxX20Protocol for all 163 documented X20 payload variants, including poll/data layouts sharing one ID. Choose one UBX registration per protocol builder. The standard registration retains its 8 KB frame buffer; the explicit X20 profile accepts the full UBX length range with a bounded 65,543-byte buffer.

Message model
`UbxAckAck`
`UbxAckNak`
`UbxCfgAnt`
`UbxCfgCfg`
`UbxCfgMsg`
`UbxCfgNav5`
`UbxCfgPrt`
`UbxCfgRate`
`UbxCfgRst`
`UbxCfgTMode3`
`UbxInfDebug`
`UbxInfError`
`UbxInfNotice`
`UbxInfTest`
`UbxInfWarning`
`UbxMonHw`
`UbxMonMsgpp`
`UbxMonRxbuf`
`UbxMonTxbuf`
`UbxMonVer`
`UbxNavDop`
`UbxNavPvt`
`UbxNavSat`
`UbxNavSbas`
`UbxNavStatus`
`UbxNavSvin`
`UbxRxmSfrbx`

Usage and limitations

Receiver firmware determines which commands and payload versions are accepted. Registration does not configure receiver output. Use the receiver microservice for request/response workflows and acknowledgements. The standalone UbxMessageFactory is empty; use RegisterUbxProtocol. Existing payload models implement IVisitable; see Quick Start for field traversal and its editing constraints.

X20 additions preserve existing property signatures and native wire offsets. UbxNavPvt.Flags3 retains all 16 raw bits, including correction-age and authentication indicators. UbxRxmSfrbx.SigId aliases the former reserved byte; navigation-word projections are restricted to supported legacy GPS/GLONASS signals. NAV-STATUS indoor-detection and selective-L5 field definitions are firmware-gated in the manufacturer PDF (protocol 52.00 or later); their presence in a model does not mean firmware 50.11 provides those features. The explicit X20 models use native integer values with scale/unit metadata, while legacy models retain their existing converted units.

Several legacy NAV, MON-VER, and RXM-SFRBX serializers remain read-only. The new X20 models have separate read/write implementations; selecting the X20 profile does not alter those legacy serializer contracts.

Implementation reference

Coverage above follows Protocols/Ubx/UbxProtocol.cs under src/Asv.Gnss. Inspect concrete message classes for field names, units, and supported payload revisions.

Legacy M8 specification message catalog

Source: Protocols/Ubx/Docs/u-blox8-M8_ReceiverDescrProtSpec_UBX-13003221.pdf, UBX-13003221 R23, section 32.7 (PDF pp. 190-195). Each mnemonic is listed once; poll/output variants and payload versions share a row. MGA subtype mnemonics remain separate even when class/ID is shared.

This historical table inventories the legacy M8 models only. Additional X20 models and their exact variants are listed in the separate X20 catalog; an X20 model does not establish compatibility with every M8 payload revision.

Status: Model present means a concrete payload model exists in the current checkout; it does not certify complete field, revision, encoding, or firmware coverage. Partial identifies a known incomplete decoder. Not implemented means no matching concrete model was found. Default reports whether the standard registration adds that model. Models outside the default set require explicit registration. See the limitations above before transmitting messages.

Page references below are PDF page numbers (1-based), including covers and front matter.

Class / ID	Message	Status	C# model	Default	PDF pages
0x05 / 0x01	ACK-ACK	Model present	`UbxAckAck`	Yes	196
0x05 / 0x00	ACK-NAK	Model present	`UbxAckNak`	Yes	196
0x0B / 0x30	AID-ALM	Not implemented	-	No	197, 198
0x0B / 0x33	AID-AOP	Not implemented	-	No	199, 200
0x0B / 0x31	AID-EPH	Not implemented	-	No	201, 202
0x0B / 0x02	AID-HUI	Not implemented	-	No	203
0x0B / 0x01	AID-INI	Not implemented	-	No	205
0x06 / 0x13	CFG-ANT	Model present	`UbxCfgAnt`	Yes	208
0x06 / 0x93	CFG-BATCH	Not implemented	-	No	209
0x06 / 0x09	CFG-CFG	Model present	`UbxCfgCfg`	Yes	210
0x06 / 0x06	CFG-DAT	Not implemented	-	No	212, 213
0x06 / 0x70	CFG-DGNSS	Not implemented	-	No	214
0x06 / 0x61	CFG-DOSC	Not implemented	-	No	214
0x06 / 0x56	CFG-ESFALG	Not implemented	-	No	216
0x06 / 0x4C	CFG-ESFA	Not implemented	-	No	217
0x06 / 0x4D	CFG-ESFG	Not implemented	-	No	218
0x06 / 0x82	CFG-ESFWT	Not implemented	-	No	218
0x06 / 0x60	CFG-ESRC	Not implemented	-	No	221
0x06 / 0x69	CFG-GEOFENCE	Not implemented	-	No	223
0x06 / 0x3E	CFG-GNSS	Not implemented	-	No	224
0x06 / 0x5C	CFG-HNR	Not implemented	-	No	227
0x06 / 0x02	CFG-INF	Not implemented	-	No	227, 228
0x06 / 0x39	CFG-ITFM	Not implemented	-	No	229
0x06 / 0x47	CFG-LOGFILTER	Not implemented	-	No	230
0x06 / 0x01	CFG-MSG	Model present	`UbxCfgMsg`	Yes	232, 233
0x06 / 0x24	CFG-NAV5	Model present	`UbxCfgNav5`	Yes	233
0x06 / 0x23	CFG-NAVX5	Not implemented	-	No	236, 238, 241
0x06 / 0x17	CFG-NMEA	Not implemented	-	No	243, 245, 248
0x06 / 0x1E	CFG-ODO	Not implemented	-	No	251
0x06 / 0x3B	CFG-PM2	Not implemented	-	No	252, 254, 256
0x06 / 0x86	CFG-PMS	Not implemented	-	No	259
0x06 / 0x00	CFG-PRT	Model present	`UbxCfgPrt`	Yes	260, 263, 265, 268
0x06 / 0x57	CFG-PWR	Not implemented	-	No	270
0x06 / 0x08	CFG-RATE	Model present	`UbxCfgRate`	Yes	271
0x06 / 0x34	CFG-RINV	Not implemented	-	No	272
0x06 / 0x04	CFG-RST	Model present	`UbxCfgRst`	Yes	273
0x06 / 0x11	CFG-RXM	Not implemented	-	No	275
0x06 / 0x16	CFG-SBAS	Not implemented	-	No	276
0x06 / 0x88	CFG-SENIF	Not implemented	-	No	278
0x06 / 0x8D	CFG-SLAS	Not implemented	-	No	279
0x06 / 0x62	CFG-SMGR	Not implemented	-	No	280
0x06 / 0x64	CFG-SPT	Not implemented	-	No	283
0x06 / 0x3D	CFG-TMODE2	Not implemented	-	No	283
0x06 / 0x71	CFG-TMODE3	Model present	`UbxCfgTMode3`	Yes	285
0x06 / 0x31	CFG-TP5	Not implemented	-	No	287, 288, 289
0x06 / 0x53	CFG-TXSLOT	Not implemented	-	No	291
0x06 / 0x1B	CFG-USB	Not implemented	-	No	292
0x10 / 0x14	ESF-ALG	Not implemented	-	No	294
0x10 / 0x15	ESF-INS	Not implemented	-	No	295
0x10 / 0x02	ESF-MEAS	Not implemented	-	No	297
0x10 / 0x03	ESF-RAW	Not implemented	-	No	298
0x10 / 0x10	ESF-STATUS	Not implemented	-	No	299
0x28 / 0x01	HNR-ATT	Not implemented	-	No	302
0x28 / 0x02	HNR-INS	Not implemented	-	No	303
0x28 / 0x00	HNR-PVT	Not implemented	-	No	304
0x04 / 0x04	INF-DEBUG	Model present	`UbxInfDebug`	Yes	307
0x04 / 0x00	INF-ERROR	Model present	`UbxInfError`	Yes	307
0x04 / 0x02	INF-NOTICE	Model present	`UbxInfNotice`	Yes	308
0x04 / 0x03	INF-TEST	Model present	`UbxInfTest`	Yes	308
0x04 / 0x01	INF-WARNING	Model present	`UbxInfWarning`	Yes	309
0x21 / 0x11	LOG-BATCH	Not implemented	-	No	310
0x21 / 0x07	LOG-CREATE	Not implemented	-	No	313
0x21 / 0x03	LOG-ERASE	Not implemented	-	No	314
0x21 / 0x0E	LOG-FINDTIME	Not implemented	-	No	314, 315
0x21 / 0x08	LOG-INFO	Not implemented	-	No	316
0x21 / 0x10	LOG-RETRIEVEBATCH	Not implemented	-	No	318
0x21 / 0x0F	LOG-RETRIEVEPOSEXTRA	Not implemented	-	No	319
0x21 / 0x0B	LOG-RETRIEVEPOS	Not implemented	-	No	319
0x21 / 0x0D	LOG-RETRIEVESTRING	Not implemented	-	No	320
0x21 / 0x09	LOG-RETRIEVE	Not implemented	-	No	321
0x21 / 0x04	LOG-STRING	Not implemented	-	No	322
0x13 / 0x60	MGA-ACK-DATA0	Not implemented	-	No	323
0x13 / 0x20	MGA-ANO	Not implemented	-	No	324
0x13 / 0x03	MGA-BDS-EPH	Not implemented	-	No	325
0x13 / 0x03	MGA-BDS-ALM	Not implemented	-	No	326
0x13 / 0x03	MGA-BDS-HEALTH	Not implemented	-	No	327
0x13 / 0x03	MGA-BDS-UTC	Not implemented	-	No	328
0x13 / 0x03	MGA-BDS-IONO	Not implemented	-	No	328
0x13 / 0x80	MGA-DBD	Not implemented	-	No	329
0x13 / 0x21	MGA-FLASH-DATA	Not implemented	-	No	330
0x13 / 0x21	MGA-FLASH-STOP	Not implemented	-	No	331
0x13 / 0x21	MGA-FLASH-ACK	Not implemented	-	No	331
0x13 / 0x02	MGA-GAL-EPH	Not implemented	-	No	332
0x13 / 0x02	MGA-GAL-ALM	Not implemented	-	No	334
0x13 / 0x02	MGA-GAL-TIMEOFFSET	Not implemented	-	No	335
0x13 / 0x02	MGA-GAL-UTC	Not implemented	-	No	335
0x13 / 0x06	MGA-GLO-EPH	Not implemented	-	No	336
0x13 / 0x06	MGA-GLO-ALM	Not implemented	-	No	337
0x13 / 0x06	MGA-GLO-TIMEOFFSET	Not implemented	-	No	338
0x13 / 0x00	MGA-GPS-EPH	Not implemented	-	No	339
0x13 / 0x00	MGA-GPS-ALM	Not implemented	-	No	341
0x13 / 0x00	MGA-GPS-HEALTH	Not implemented	-	No	342
0x13 / 0x00	MGA-GPS-UTC	Not implemented	-	No	342
0x13 / 0x00	MGA-GPS-IONO	Not implemented	-	No	343
0x13 / 0x40	MGA-INI-POS_XYZ	Not implemented	-	No	344
0x13 / 0x40	MGA-INI-POS_LLH	Not implemented	-	No	345
0x13 / 0x40	MGA-INI-TIME_UTC	Not implemented	-	No	345
0x13 / 0x40	MGA-INI-TIME_GNSS	Not implemented	-	No	347
0x13 / 0x40	MGA-INI-CLKD	Not implemented	-	No	348
0x13 / 0x40	MGA-INI-FREQ	Not implemented	-	No	349
0x13 / 0x40	MGA-INI-EOP	Not implemented	-	No	350
0x13 / 0x05	MGA-QZSS-EPH	Not implemented	-	No	350
0x13 / 0x05	MGA-QZSS-ALM	Not implemented	-	No	352
0x13 / 0x05	MGA-QZSS-HEALTH	Not implemented	-	No	353
0x0A / 0x32	MON-BATCH	Not implemented	-	No	354
0x0A / 0x28	MON-GNSS	Not implemented	-	No	355
0x0A / 0x0B	MON-HW2	Not implemented	-	No	357
0x0A / 0x09	MON-HW	Model present	`UbxMonHw`	Yes	358
0x0A / 0x02	MON-IO	Not implemented	-	No	359
0x0A / 0x06	MON-MSGPP	Model present	`UbxMonMsgpp`	Yes	360
0x0A / 0x27	MON-PATCH	Not implemented	-	No	360, 361
0x0A / 0x07	MON-RXBUF	Model present	`UbxMonRxbuf`	Yes	362
0x0A / 0x21	MON-RXR	Not implemented	-	No	362
0x0A / 0x2E	MON-SMGR	Not implemented	-	No	363
0x0A / 0x2F	MON-SPT	Not implemented	-	No	366
0x0A / 0x08	MON-TXBUF	Model present	`UbxMonTxbuf`	Yes	370
0x0A / 0x04	MON-VER	Model present	`UbxMonVer`	Yes	371
0x01 / 0x60	NAV-AOPSTATUS	Not implemented	-	No	373
0x01 / 0x05	NAV-ATT	Not implemented	-	No	374
0x01 / 0x22	NAV-CLOCK	Not implemented	-	No	375
0x01 / 0x36	NAV-COV	Not implemented	-	No	375
0x01 / 0x31	NAV-DGPS	Not implemented	-	No	376
0x01 / 0x04	NAV-DOP	Model present	`UbxNavDop`	Yes	377
0x01 / 0x3D	NAV-EELL	Not implemented	-	No	378
0x01 / 0x61	NAV-EOE	Not implemented	-	No	379
0x01 / 0x39	NAV-GEOFENCE	Not implemented	-	No	379
0x01 / 0x13	NAV-HPPOSECEF	Not implemented	-	No	380
0x01 / 0x14	NAV-HPPOSLLH	Not implemented	-	No	381
0x01 / 0x28	NAV-NMI	Not implemented	-	No	383
0x01 / 0x09	NAV-ODO	Not implemented	-	No	386
0x01 / 0x34	NAV-ORB	Not implemented	-	No	387
0x01 / 0x01	NAV-POSECEF	Not implemented	-	No	390
0x01 / 0x02	NAV-POSLLH	Not implemented	-	No	390
0x01 / 0x07	NAV-PVT	Model present	`UbxNavPvt`	Yes	391
0x01 / 0x3C	NAV-RELPOSNED	Not implemented	-	No	394
0x01 / 0x10	NAV-RESETODO	Not implemented	-	No	396
0x01 / 0x35	NAV-SAT	Model present	`UbxNavSat`	Yes	396
0x01 / 0x32	NAV-SBAS	Model present	`UbxNavSbas`	Yes	398
0x01 / 0x42	NAV-SLAS	Not implemented	-	No	400
0x01 / 0x06	NAV-SOL	Not implemented	-	No	402
0x01 / 0x03	NAV-STATUS	Model present	`UbxNavStatus`	Yes	403
0x01 / 0x30	NAV-SVINFO	Not implemented	-	No	405
0x01 / 0x3B	NAV-SVIN	Model present	`UbxNavSvin`	Yes	407
0x01 / 0x24	NAV-TIMEBDS	Not implemented	-	No	409
0x01 / 0x25	NAV-TIMEGAL	Not implemented	-	No	410
0x01 / 0x23	NAV-TIMEGLO	Not implemented	-	No	411
0x01 / 0x20	NAV-TIMEGPS	Not implemented	-	No	412
0x01 / 0x26	NAV-TIMELS	Not implemented	-	No	413
0x01 / 0x21	NAV-TIMEUTC	Not implemented	-	No	415
0x01 / 0x11	NAV-VELECEF	Not implemented	-	No	416
0x01 / 0x12	NAV-VELNED	Not implemented	-	No	417
0x02 / 0x61	RXM-IMES	Not implemented	-	No	418
0x02 / 0x14	RXM-MEASX	Not implemented	-	No	421
0x02 / 0x41	RXM-PMREQ	Not implemented	-	No	422, 423
0x02 / 0x15	RXM-RAWX	Not implemented	-	No	424, 428
0x02 / 0x59	RXM-RLM	Not implemented	-	No	431, 432
0x02 / 0x32	RXM-RTCM	Not implemented	-	No	433
0x02 / 0x13	RXM-SFRBX	Model present	`UbxRxmSfrbx`	Yes	434, 435
0x02 / 0x20	RXM-SVSI	Not implemented	-	No	436
0x27 / 0x03	SEC-UNIQID	Not implemented	-	No	438
0x0D / 0x11	TIM-DOSC	Not implemented	-	No	439
0x0D / 0x16	TIM-FCHG	Not implemented	-	No	439
0x0D / 0x17	TIM-HOC	Not implemented	-	No	440
0x0D / 0x13	TIM-SMEAS	Not implemented	-	No	441
0x0D / 0x04	TIM-SVIN	Not implemented	-	No	443
0x0D / 0x03	TIM-TM2	Not implemented	-	No	444
0x0D / 0x12	TIM-TOS	Not implemented	-	No	445
0x0D / 0x01	TIM-TP	Not implemented	-	No	447
0x0D / 0x15	TIM-VCOCAL	Not implemented	-	No	449, 450, 451
0x0D / 0x06	TIM-VRFY	Not implemented	-	No	452
0x09 / 0x14	UPD-SOS	Not implemented	-	No	453, 454, 455

All protocols

22 October 2026