RS-422 signal using AB DF-1 - maximum length

[DrDrreeeaaa]

Hi all

I am designing an interface between a CompactLogix PLC and a Kingfisher RTU located in the field. The RTU is about 100m from the PLC.

I have used RS-422 due to the distance. The RTU (CP-11) supports comms with an AB PLC using DF1, and the RTU has an RS-422 capable serial port.

I will be connecting to the PLC using a prosoft card - MVI69-DFCM - which provides a DF1 master/slave interface to the CompactLogix PLC. I think it supports RS-422 - but I'm not sure and this is where I would be greatful for a hand...

1) I assume DF-1 protocol over RS-422 signals is possible
2) If each of the master/slave devices (in this case, prosoft card and RTU) support DF1 on their RS-422 capable ports - can I communicate RS422 DF1 between them

3) Since it is RS-422 I assume my 100m run will not be a problem

Thanks guys

Michael