R
Dear List,
We have a customer with an Modicon 984 that is communicated to via an analogue modem link (Gandalf modems at 9600bps to be precise).
There are actually three sets of modems for the various communications signals (HMI, programming and ancillary data channel).
The HMI gets to the PLC via a Bridge Mux BM-85.
The Modicon 984 is to be replaced with a Quantum PLC. The analogue link is to be replaced with a fibre-optic link.
My question is which would be a better approach:
Approach 1:
Add Modbus over TCP/IP to the Quantum PLC and switches at either end.
Obviously some re-jigging of the communications because the Mux is being by-passed. Other ancillary traffic would be routed through the TCP/IP fibre link by TCP/IP - Serial protocol converters. There is some concern about traffic between the HMI and other devices attached to the Bridge Mux that would need to be re-routed. Perhaps a protocol converter would also be required to keep that aforementioned link.
Approach 2:
Do not add Modbus over TCP/IP to the Quantum PLC and just use fibre-optic modems. Obviously one trunk line per system and new modems. Everything
else remains the same.
I would appreciate any opinions on why we would prefer Approach 1 over Approach 2. Approach 2 appears to be cheaper and involve a little less engineering, but we are keen to add Ethernet TCP/IP and make use of the diagnostic capabilities of the Quantum PLC that are available via Ethernet.
I would be interested from hearing from Quantum users who started at the 984 and added Ethernet.
Thanks
RA
We have a customer with an Modicon 984 that is communicated to via an analogue modem link (Gandalf modems at 9600bps to be precise).
There are actually three sets of modems for the various communications signals (HMI, programming and ancillary data channel).
The HMI gets to the PLC via a Bridge Mux BM-85.
The Modicon 984 is to be replaced with a Quantum PLC. The analogue link is to be replaced with a fibre-optic link.
My question is which would be a better approach:
Approach 1:
Add Modbus over TCP/IP to the Quantum PLC and switches at either end.
Obviously some re-jigging of the communications because the Mux is being by-passed. Other ancillary traffic would be routed through the TCP/IP fibre link by TCP/IP - Serial protocol converters. There is some concern about traffic between the HMI and other devices attached to the Bridge Mux that would need to be re-routed. Perhaps a protocol converter would also be required to keep that aforementioned link.
Approach 2:
Do not add Modbus over TCP/IP to the Quantum PLC and just use fibre-optic modems. Obviously one trunk line per system and new modems. Everything
else remains the same.
I would appreciate any opinions on why we would prefer Approach 1 over Approach 2. Approach 2 appears to be cheaper and involve a little less engineering, but we are keen to add Ethernet TCP/IP and make use of the diagnostic capabilities of the Quantum PLC that are available via Ethernet.
I would be interested from hearing from Quantum users who started at the 984 and added Ethernet.
Thanks
RA