Serial to Ethernet

[drusso 0]

I'm looking to add another panelview plus ethernet screen to an existing Control Logix system. The added location is in a seperate building about 500 feet from the existing panelview plus terminal. The only existing cable is a serial cable that was used back in the VDT100 termianl days. Can I use a 2 1761-NET-ENI to convert the ethernet to serial back to ethernet ? Thanks, drusso

[Ken Roach 194]

No. The 1761-NET-ENI serial port has to be connected to a controller, and cannot be connected to a network bridge or another NET-ENI. What you're really looking for is an Ethernet extender. I've seen these, for example, in hotels where the twisted-pair phone wiring was used to carry TCP traffic from a central switch to in-room adapters. You can only get a few Mb/s out of these, but it is certainly fast enough for simple HMI connectivity. Patton Electronics (www.patton.com) and Black Box are two good vendors for this sort of equipment.

[drusso 0]

Thanks for the quick answer. I sent an email to Patton for a price quote. thanks, drusso

[Nathan 7]

A few options depending on what you're doing: 1. If the range is reasonably close to the envelope just put a switch in between. It'll amplify the signal. This is considered to be tacky and certainly can't scale, but could do the trick for you. 2. The "standard" thing to do is usually put in switches at both locations with fibre uplinks between them (or a single switch on one end and a fibre ethernet bridge on the other). Not cheap, but very reliable, scalable, and fast. 3. This is a really cool option. Black Box sells VDSL devices (modems or something like it) that will get you a 1.4 megabit connection at least a mile over a single twisted pair. We ran these things with crappy cable under rail tracks, spliced them all over the place, and they still worked like a champ over a mile (temporary setup, of course). 4. High gain directional antennas and wireless setups are relatively cheap and simple these days. Depends on line of sight and interference. 5. I don't really know the difference between Ethernet "extenders" and "repeaters". I know that fancy ones (layer 3 or 4) will be TCP/IP aware, incrementing the TTL as it extends the signal. If you have an IT department there, they should be able to help you.