modbus plus ethernet bridge

H all,
At the moment our modicon modbus plus network consists of 6 of 984 processors, two plc programming workstations and two Citect servers.The two workstations and two servers have SA-85 cards in them and the modbus plus cable connects directly to the back of all the pcs.I need to add a 3rd plc programming station to this network but unfortunately it is too far away to run the modbus plus cable all the way to this pc.The idea I am toying with now is a bridge to ethernet and picking up over the ethernet using a 174-CEV-200-30 bridge, has anyone ever used one of these before and will I be able to config citect to use this bridge instead of the SA-85 cards in the future if they fail??? or perhaps there is a better solution????We are using Proworx NXT v2.21 for programming and Citect v5.21 for the SCADA.Any ideas or suggestions will be appreciated.
Tom

The standard Modbus Plus network has a 1500 ft. limitation. You can double this length to 3000 ft by using a Repeater (RR85) and can use up to 3 Repeaters in the network for a total length of 6000 ft.

I haven't yet used ethernet to connect to the Modbus Plus network, maybe someone else can answer your questions on that.

If you don't already have it you can get the Modbus Plus Network Planning and Installation Guide here

Have you looked at going from Modbus Plus copper wire to Modbus Plus fibre optic and then back to copper instead? You can get these transceivers from Schneider Electric (Modicon) as well as third party vendors.

Netvisor,

I have used the 174 CEV 300 10 Ether to Modbus bridges with success. I use Ethernet over a fiber network to get to a remote comm site where I use the bridge to convert to Modbus and on out through a serial radio modem to the remote pumping sites. This setup has been very reliable after it was well protected from dirty power and lightning strikes. It was getting blown up regularly before that. I would guess that the Modbus Plus model would serve you well. The configuration is a little tricky to get the hang of but not too awful bad.

Steve

Hi Netvisor,
You got all that is required to hook up the third programming terminal. If you have a ethernet link between the 3rd programming terminal and one of your existing programming terminal with a SA-85, configure your remote server at the existing terminal and configure remote client at the 3rd terminal. The help files with the WInconx got the details, i have tried this before, it works....

Regards
P Ganasa