Vexa Max: Long-Range Hydroacoustic Modem
Vexa Max Distance covered
Capacity delivered
Vexa Max is an acoustic modem with the antenna gain and receiver sensitivity to extend reliable communication to 3000 m — compact enough for ROV and AUV payload bays.
What it does
- Bidirectional data transmission — the modem sends and receives digital data between underwater points up to 3000 m apart
- Dual transmission modes — the modem runs a transparent pass-through channel for raw data or packet mode with guaranteed, confirmed delivery
- Built-in ranging and depth sensing — the modem calculates distance from signal propagation time and reads depth from its built-in sensor, no external hardware needed
- Networked multi-unit access — the modem addresses individual subscribers on a shared channel and requests depth, temperature or supply-voltage readings from any unit in range
Distinctive features
- Ø64 × 62 mm, 360 g — a fit for ROV skids, sensor frames and diver harnesses
- 0.33 W receive, 15 W transmit — headroom for extended-range performance
- Four selectable baud rates, 78 to 634 bit/s — range-speed trade-off, set by the mission
- Full CDMA compatibility — shared addressing with Vexa Mini and Vexa Locator for mixed-fleet deployments
Some operations don't fit inside 1000 metres — deep survey transects, long tether-free ROV runs, sensor networks spread across a wide seabed. Vexa Max is built for the reach those jobs need. The same antenna platform as the rest of the family carries a signal three times as far as Vexa Mini — out to 3000 metres — in a body that grows to just Ø64 × 62 mm and 360 grams. That extra reach scales in capacity too: as many as 254 individually addressed subscribers can share the full 3000-by-3000-metre water area Max now covers. Run it as a transparent pass-through for raw data, or switch to packet mode when every message needs a confirmed delivery — the same choice every Vexa modem gives you. Three times the reach. A whole area's worth of capacity. One family, one protocol.
System components
Downloads
Full specifications (PDF, 126 KB)Specifications
Acoustics
| Operating range | 3000 m |
|---|---|
| Payload data rate | 78 / 156 / 314 / 634 bit/s |
| Bit error rate | 10⁻⁶ |
| SNR | −2 dB |
| Max. relative velocity | ±1 m/s |
| Carrier frequency | 20050 Hz |
| Max. acoustic source level (in-band) | 175 dB re 1 µPa @ 1 m |
Electrical
| Supply voltage | 5 – 12 V |
|---|---|
| Data lines voltage | 0 – 3.3 V |
| Data lines output impedance | 1 kOhm |
| Rated startup time | 100 ms |
| Power consumption (Rx / Tx) | 0.33 W / 15 W |
Interface
| Interface | UART 9600 bit/s |
|---|---|
| Communication protocol | NMEA 0183 PUWV |
| Subscribers division | Up to 20 code channels |
| Packet mode | 254 addresses, broadcast, up to 64 bytes/packet |
Mechanical
| Dimensions (Ø × h) | 64 × 62 mm |
|---|---|
| Weight (dry) | 0.36 kg |
| Cable length / diameter | 0.5 m / 5 mm |
Environment
| Operating depth | 300 m |
|---|---|
| Working temperature | −5 … +50 °C |
Request a quote for Vexa Max
Tell us about your project and an engineer will help you specify the right configuration of the Vexa Max. We reply within 1 business day.