Product Details
B921 Class B AIS Transceiver - 2W CSTDMA
**As the FCC requires all units sold in the US to be programmed by a qualified technician. Please submit the form below for programming at the time of purchase. A copy of the MMSI registration or FCC Ship Station License is required along with the vessel master or owner's signature on the completed programming form.**
The B921 is a 2W CSTDMA Class B AIS transceiver, delivering em-trak's advanced performance and reliability through next-gen technology. Small and durable, this trusted transceiver processes all AIS transmissions in real-time, even at the range limit, so you always have the complete picture and the time to respond.
em-trak's intelligent connectivity means the B921 can be connected to any chart-plotter and comes equipped with integrated GPS technology and best-in-class, ultra-low power consumption. Installation is also simplified with our unique FLEXI-FIT® bracket system to have you up and running in no time at all.
Features:
- Certified AIS Class B – 2W CSTDMA
- Global certification - USCG / FCC / Canada / Europe
- SRT-AIS™ Transceiver Engine for superlative proven performance
- FLEXI-FIT™ bracket system for easy, convenient, and secure installation
- Internal high-performance GPS receiver and antenna (external antenna optional)
- Water, pressure spray, and damp proof (IPx6, IPx7 certified)
- Protected from vibration, shock, and extreme temperatures
- Small and lightweight
- Ultra-low power consumption – best in class
- NMEA 0183 & NMEA 2000
- Automated health and performance monitoring
- Silent mode (transmit-off) function
- Enhanced RF screening to protect against electromagnetic interference
- Built-in power surge protection
Physical & Environmental Specifications:
- Size (H x W x D): 150 x 115 x 45mm
- Weight: 375kg
- Operating temperature: -25°C to +55°C
- Storage temperature: -25°C to +70°C
- Ingress protection: IPx6 and IPx7
Electrical Specifications:
- Supply voltage: 12V or 24V DC
- Supply voltage range: 9.6V - 31.2V DC
- Average current (at 12V): 135mA
- Peak current: 2A
- Average power consumption (at 12V): 1.6W
- Galvanic isolation: NMEA 0183, NMEA 2000, VHF antenna port
Connectors:
- VHF antenna: SO-239
- GNSS: TNC
- Power: 12-way circular multipole
- NMEA 2000: 5-way Micro-C connector
- USB: USB Micro-B
Data Interfaces:
- NMEA 0183: 2 x bi-directional ports
- NMEA 2000: NMEA 2000 Ed 3.101, LEN=1
- USB: PC virtual com port for NMEA 0183 data
Standards Compliance:
- AIS standards: IEC 62287-1 Ed. 3, ITU-R M.1371.5
- Product safety standards: EN60950-1 2006 +A11:2009 +A1:2010 +A12:2011 +A2:2013 EN62311:2008
- Environmental standards: IEC 60945 Ed. 4
- Serial data interface standards: IEC 61162-1 Ed 5.0, IEC 61162-2 Ed 1.0
- NMEA 2000: NMEA 2000 Ed 3.101
- GNSS performance standards: IEC 61108-1 Ed 2.0, IEC 61108-02 Ed 1.0
GNSS:
- Systems supported: GPS, GLONASS, BeiDou, Galileo (two of any combination, three including GPS, Galileo)
- Channels: 72
- Internal/external antenna: Internal or optional external antenna
- Time to first fix from the cold start: 26s
VHF Transceiver:
- VDL access scheme: CSTDMA
- Operating frequency: 156.025MHz - 162.025MHz
- Channel bandwidth: 25kHz
- Receivers/transmitters: 2 x receivers, 1 x transmitter
- AIS receiver sensitivity (20% PER): -111dBm
- AIS transmitter power: 2W (+33dBm)
User Interface:
- Indicators: Power, transmit timeout, error, silent mode
In the Box:
- 1 x AIS transceiver
- 1 x Power and data cable (2M)
- 1 x FLEXI-FIT™ mounting bracket
- Complete with screws & optional fixing tape
Specifications:
- AIS Class: B
- Antenna Included: Yes
- Display Included: No
- Function: Receive/Transmit
- GPS Included: Yes
- Box Dimensions: 6"H x 7"W x 8"L WT: 1.55 lbs
- UPC: 672975210502
Quick Guide (pdf)
Brochure (pdf)

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