Automation Professionals' Advanced Modbus Driver

[jespinmartin1]

@pturmel

For any practical purpose, use unit #0 only with Modbus TCP devices that expect it to behave like any other unit number.

Sure, I've testing over TCP and the broadcast unit and the device disconnects and only recovers manual on save again on the gateway.

@pturmel

Don't use rawModbus() for operations on Modbus addresses that have proper OPC Item support in the driver

Sure, I was using the function for bulks HR writes with codes 16/23.

@pturmel

Also do not use rawModbus() for any packet exchange where you cannot exactly predict the response payload size. (After the echoed function code, not including the CRC.)

When using RTU over TCP the CRC is not important after all, right? So, the payload size should be always be expected.

@pturmel, would you verify on your code if the device crashes when using unit = 0?

[pturmel]

@jespinmartin1

When using RTU over TCP the CRC is not important after all, right?

Not correct. RTU over TCP simply means the actual serial port is remote, but all other serial semantics apply, including the CRC.

@jespinmartin1

if the device crashes when using unit = 0?

Not supported on RTU. I might have time to experiment with unsupported functionality in July or August. Getting my modules ready for v8.3 is second only to bugfixes now.