Waveshare Industrial 8-Channel Analog Acquisition Module 0-20mA RS485

The module typically requires configuration via hardware DIP switches or specific Modbus holding registers. Consult the product datasheet for the exact register map. Common parameters like device ID (1-247) and baud rate (4800 to 256000 bps) are set by writing to the appropriate configuration registers using a Modbus master tool before network deployment, ensuring no address conflicts occur on the RS485 bus.

Connect the positive wire from your 2-wire 4-20mA sensor loop to the module's channel positive terminal and the negative wire to the channel negative terminal, ensuring the module's internal shunt resistor is configured for current mode. The wide 7-36V power input can often power the sensor loop itself. Always verify polarity and use shielded cable for long runs to minimize electrical noise interference on the analog signal.

Yes, the module supports both voltage and current inputs. You must configure the input mode, often via hardware jumpers or software commands, to match your sensor's output (e.g., 0-10V). The 12-bit ADC will digitize the voltage signal. Ensure the input voltage does not exceed the module's specified maximum input range to prevent damage to the analog front-end circuitry.

For a multi-drop RS485 network, connect the 'A' and 'B' data lines from the master device to the corresponding 'A' and 'B' terminals on the first module. Then, daisy-chain from that module's output terminals to the next module's input, maintaining the same polarity. Terminate the bus with a 120-ohm resistor across the 'A' and 'B' lines at the farthest end device only to prevent signal reflections and ensure reliable Modbus communication.