Dear all,

I am facing problem while addressing multiple slaves in my modbus code.

viz when I poll the slave with id 01 it responds properly but now if I poll for 2nd then it doesnot respond.

can any body put some light on this

regards

shravan
[email protected]

 

You didn't tell us
- if both ever worked properly or if this is commissioning
- if the slave #1 and slave #2 are identical devices or different devices

Slave #2 might
- not be connected to link/network (ethernet cable removed, wire loose)
- not be powered (fuse blown)
- be turned off (power switch)
- not be enabled (original unit replaced, Modbus not configured properly, slave ID is 99)
- have wrong serial port setup (baud rate, parity)
- have a dysfunctional serial port (lightning strike)