Update ModbusMaster.cpp

[anklimov]

Description

Add tolerance to random noise receiving after transmission in half-duplex mode (Invalid Slave 0xE1 error preventing)

Awaiting for 1-s byte of response == SlaveID. All garbage before - discarding

[rnicolas]

Hi @anklimov
I had the same problem, but in my case the noise was always zero, so instead of comparing the readings from serial with the direction in order to know were the frame started, I just discarded all zero values until I read a non 0 value. Do you have random value readings before you read the slave ID?

[anklimov]

Hi ! In my case, I definitely saw non-zero noise values time-by time Since the fact, correct reply always started with slave ID suggested method looks more reliable if no appropriate SlaveID received for the response time - Timeout error will occurs

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On Jan 15, 2018, at 1:16 AM, rnicolas ***@***.***> wrote: Hi @anklimov <https://github.com/anklimov> I had the same problem, but the noise was always zero, so instead of comparing the readings from serial with the direction in order to know were the frame started, I just discarded all zero values until I read a non 0 value. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#98 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AVhOGcbKrkWKOocazokCTR2zzGM9Dk0dks5tKnyngaJpZM4Rdud_>.

[rnicolas]

@anklimov
Ok! Thanks! I'll update my code to be like yours because it's more generic.