Vexa Mini hydroacoustic modems

The key advantages of the Vexa Mini modem are its small size and weight – just 41 by 45 mm with a dry weight of 0.16 kg – low power consumption (Rx/Tx) of 0.33/6 W, and ease of use with no setup or calibration. Immediately after power-on, the user gets a transparent channel that requires no knowledge of the modem's control protocol.

Ideal for controlling autonomous underwater vehicles and for data transmission in user applications.

Vexa Max provides digital hydroacoustic communication between 254 subscribers: in code mode, transparent channel mode, or packet mode with logical addressing and guaranteed delivery. Extremely small size, low power consumption and ease of use make the Vexa family of modems a solution for controlling autonomous underwater devices and transmitting data in size- and weight-sensitive applications.

The device lets you: transmit data in transparent channel mode (simply connect the modem to a serial port); request the depth, temperature and supply voltage of remote Vexa family modems, with simultaneous measurement of the signal propagation time (and hence the distance to them); transmit data in packet mode with guaranteed delivery (ALO — At-least-once) and delivery notification; and measure its own immersion depth, water temperature and supply voltage.

Devices in the Vexa family use a simple NMEA-like configuration protocol, and the supplied open-source uWaveLib (.NET) and uWave ALibs (Arduino) libraries make it as simple and fast as possible to integrate the modems into custom solutions.

Differences from the base Vexa Mini version: maximum communication range increased to 3000 m (when working with another Vexa Max, Vexa Max OEM or Vexa Locator; with standard Vexa Mini modems the range is 1000 m). The monoblock design is patented (patent RU2659299C1).

Vexa Max OEM is based on the UTRO platform and is supplied as a PCB module with an RT-1.524525-1 hydroacoustic antenna — without its own enclosure, for embedding into the customer's product. It provides digital hydroacoustic communication between 254 subscribers: in code mode, transparent channel mode, or packet mode with logical addressing and guaranteed delivery. Extremely small size, low power consumption and ease of use make the Vexa family of modems a solution for controlling autonomous underwater devices and transmitting data in size- and weight-sensitive applications.

The device lets you: transmit data in transparent channel mode — simply connect the modem to a serial port; request the depth, temperature and supply voltage of remote Vexa family modems, with simultaneous measurement of the signal propagation time (and hence the distance to them); and transmit data in packet mode with guaranteed delivery (ALO — At-least-once) and delivery notification.

Differences from the base Vexa Mini version: maximum communication range increased to 3000 m (when working with another Vexa Max OEM, Vexa Max or Vexa Locator; with standard Vexa Mini modems it is 1000 m); an OEM version without an enclosure; no built-in depth/temperature sensor.

Vexa Locator is a device that combines the functions of hydroacoustic data transmission and an ultra-short baseline (USBL) navigation system.

Using Vexa Locator modems, the user can: transmit arbitrary user data between Vexa Locator, Vexa Max and Vexa Mini modems in any combination, with simultaneous determination of the horizontal angle of arrival; locate Vexa Locator, Vexa Max and Vexa Mini modems in command mode by range and horizontal angle of arrival; send up to 9 short code-based telecontrol commands; request the depth, temperature and supply voltage of remote modems; and measure its own depth, temperature, roll and pitch angles.

Devices in the Vexa family use a simple NMEA-like configuration protocol, and the supplied open-source uWaveLib (.NET) and uWave ALibs (Arduino) libraries make it as simple and fast as possible to integrate the modems into custom solutions. The monoblock design is patented (patent RU2659299C1).

Structurally, Vexa Locator is housed in the same enclosure as the VigilArc Array direction-finding antenna of the VigilArc USBL navigation system — the devices are outwardly indistinguishable. However, they are functionally different instruments: Vexa Locator transmits arbitrary user data and determines range and angle to any Vexa family modem, while VigilArc Array is the direction-finding station of the VigilArc system, working with VigilArc Tag responder beacons.