nanoMODBUS
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debevv
Timing
Hi, basically it doesn't. It behaves similarly to libmodbus (https://github.com/stephane/libmodbus/commit/a11805cbfda23da36aed84bca3c5edc1413d664c and https://github.com/stephane/libmodbus/issues/18). We addressed this some time ago with another user in this issue.
I thought about implementing it at the time, but it would make the library more complex both internally and for the user. Also in my experience I never found a device honoring those timings, so having the library not rely on them makes it definitely more robust.
Would you mind explaining me your use case?
Actually, I want to use this library to communicate with PLC devices, I don't have any idea this lack of timing may cause problem or not.
Sorry, can you point me to the exact line? Because I can't find it in the linked file.
By the way, if those PLC devices do follow the spec about the timings, there are two cases:
- when you receive data from them, there shouldn't be any problems because nanomodbus ignores the the intervals between characters and frames
- when you send data, I think you can get away with waiting before making a request (if you are a client), waiting before responding in a request handler (if you are a server) and spacing the characters in your write() platform function
I guess line 1277. Could you show me how to implement Write() function? I'll use this library and see there is any problem or not.
Yeah after reading my previous message again I realized that the t1,5 in the spec is not mandatory inter-character spacing but instead a timeout, so you really don't need any particular handling in your write() function.
The only things you should implement are the waits before requests and responses, to simulate inter-frame spacing