A514 Modbus Interface

The ADCON A514 Modbus Interface is an adapter than can be integrated into the following Series 4 RTUs:

• A753 GPRS/UMTS
• A755 GPRS/UMTS
• A753 UHF

Sitting inside the RTU's case the A514 can be accessed through I/O port A of the above mentioned RTU's. It uses the same digital pin as the SDI-12 bus, and can be used in parallel with SDI-12.

The A514 interface maps Modbus registers from an external device, such as a water meter or a water quality sensor, onto an SDI-12 address. Since it shares the same bus and resources, the total of all SDI-12 and Modbus sensors must not exceed 40.

Please note that most Modbus sensors have a power consumption that by far exceeds the RTU's capabilities of sensor excitation. External power must be provided to these sensors, and only the Modbus communication be connected to the RTU!

Since Modbus is by far not as well standardized as SDI-12 it is absolutely crucial that the A514 interface is properly configured. At present this is a task which only the ADCON Tech Team can execute. Should the sensor that you want to connect not be listed under the "Compatible devices" section please get in touch with your distribution partner or the ADCON sales team, by sending an email with adequate information to info@adcon.com. We will need a sample of the sensor, full technical documentation, accurately describing the sensor's registers and Endian settings, and the required cables to connect to the sensor. A flat fee applies for the testing of the sensor, the configuration of the Modbus interface, and the writing of a driver for the A850 Telemetry Gateway.