wiring with arduino as slave and by RS485 to master?

[bigplik]

hi, I appreciate if someone could explain wiring arduino with other device (master) by RS485 or RS232, when using code from this library?

I understand code provided here can act as slave for some modbus rtu master simulation on PC, but what about using it with other devices (PLC, HMI, another arduino)?

[angeloc]

Could you explain your setup? RS485 is a pretty simple bus, only 2 wires, if you correctly wire them you can talk with master or slaves

[ashrafulkhn]

In case you are trying to connect to a PLC or a HMI then connect the A and B pin of the PLC to the RS485 converter module you have used with Arduino. Make sure that A pin should be connected to A and B pin should be connected to B pin respectively (Not like tx->Rx and rx->tx).