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First off all thanks for the effort of making this plugin. An excellent initiative that gives this VFD even more value for money.
I'm sad to report that it did NOT work for me and i believe i know why.
The RS-485 standard which is used in this case states the communication allways is done using half-duplex on twowire.
This means that in someway the transceiver chip on the RS485 adapter need to be set in Transmit or Receive mode.
As i understand it it is up to the implementation to handle this (RS485 don't care as it's an interface standard and not a protocol standard).
One "normal" way to handle this with an RS232 converter, is to use the RTS pin to set the transceiver into Transmit mode, and directly afterwards the transmit lower it to
be ready to receive.
Some RS485 adapters (mostly USB to RS485) incorporate "Automatic Data Direction Controll" (ADDC), which handle the above behaviour by it's hardware.
It seems that your plugin raise the RTS all the time when its loaded thus making it only compatible with RS485 adapters that incorporates ADDC.
Other adapters can only send data, which matches well with the behaviour i get (cant see PD001,PD002 but start spindle once, get estop directly afterwards).
Conclusion:
I suggest that you update the plugin so that it raises RTS while sending and lower it directly when done.
I imagine this won't be an extreme alteration in code, but it would make the plugin compatible with the vast majority (if not all) types of RS485 interfaces/converters.
Beside that the ADDC devices are much more expensive, so those who need to buy an adapter would find this an great modification i be live.
Again thanks for your effort, it's greatly appreciated.
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