Modbus ASCII I/O Transfer

Slave – Serial Port Configuration

1. Port protocol: Modbus ASCII Slave
2. Set remaining per example
3. Set Master parameters exactly the same
4. No additional set up of Slave unit required

Master – Serial Port Configuration

1. Port protocol: Modbus ASCII Master
2. Set up per example (same as Slave)
3. Set up I/O transfers.

Action Definition

1. Name the Action
2. Read or Write
3. Select pre-configured Serial port
4. Enter destination device unique station number
5. Scan interval in seconds

Registers

1. Select the local I/O type
2. Number of registers to write
3. Input or Output
4. First Modbus register (obtained from manufacturer’s documentation) on destination device to write to.

Communications Setup

Confirm settings

The RD/TD leds demonstrate the successful Modbus poll between 2 devices