Frame generation without actual device connected

[kowalewskijan]

Hello,

are there any plans to provide an interface to have a 'Modbus frames generator' without any device actually connected? We implemented such feature for now on our fork: cthings-co@ffa6654 to see how hard is it to get it, however I'm not sure if this is just a particular edge use case we have and is it actually something worth to be mainlined.

BR,
Jan

[janiversen]

You mean something like the message_parser or package_test_tool examples ?

[kowalewskijan]

Something similar to message_parser but other way around. E.g. when issuing client.read_holding_registers(addr, count=count, slave=1), underneath it generates a binary frame, what I would like to have is instead of sending this data, retrieve the binary form and dump it to e.g. file or pipe it to other software.

[janiversen]

I do not think something like that fits inside pymodbus, since making it properly would be quite a job and basically I fail to see the upside.

Doing it outside pymodbus is very simple do not use client. use pdu.().encode() and you have what you want.

test/framer/generator.py does something like that (a bit more complex) both for requests and responses and for different framers.

examples/contrib are open for examples, remark this directory are not maintained by the pymodbus team.

[kowalewskijan]

All right. Thanks!