DH485 to Enet

[Guest Jelectric]

Any one know a way to get DH485 network to Either-net not use ContolLogixs much more like a standalone deal ENI style? Edited 9 Apr 2003 by Jelectric

[Guest PhilipW]

Hi there J, Three possibilities come to mind. 1. Are you or can you use an SLC5/05 processor? If so then you can use the Passthru functionality in the processor to bridge from the Ch0 serial port (defined as DH-485), to the Ch1 Ethernet port. This is very simple to do and simply requires setting a flag in the Status file. 2. Is there a PC in the system? If so then you can run the RSLinx Gateway functionality. Define a DH-485 driver of any kind and if you enable the gateway functionlaity in RSLinx then again you will be able to bridge to the Ethernet port. This is just the software equivalent of the first suggestion. 3. A 1770-KF3 back to back with a 1761-NET-ENI ? i.e. connect the serial ports together at the identical baud rates etc, and I would expect something to happen. The KF3 takes DH-485 packets and strips them down to RS-232 DF1 packets. The ENI should then take them and bundle then up into TCP/IP packets. I've never tried this one so I'm guessing here. (Also the KF3 isn't cheap.) Whatever approach you take the 1747-PIC or the 1761-NET-AIC+ probably won't help much as both of these devices are really just isolation/electrical convertors...they don't do any protocol conversion. It is possible that none of these suggestions above is necessarily going to work for you JElectric, for one reason or another...any other ideas out there ?? Philip Wilkie

[Rockford 0]

Has anyone tried #3 above and what was the result. Does it work? I have a Ethernet that I am installing with a SLC-5/03 a Micrologix 1200 and EZ-Automation touchscreens, but I would like to have an already existing DH485 panelview to be able to communicate over the Ethernet system without the expense of a SLC-5/05 or a PC in the system.

[JeffKiper 9]

Rockwell This is a 6 year old thread FYI. I would use a CLX chassis with a DH485 and ENBT cards (No CPU). Sorry I can't think of the exact part number for the DH4&5 card I would stay away from the other ideas. If you ever need to expand you can, If you ever need a big bad processor you have room to expand.

[paulengr 44]

Doesn't sound promising. The KF3 is a true protocol bridge between DF-1 and DH-485, so no problems there. The 1761-NET-ENI is somewhat one-way. It's really a version of a Lantronix UDS-100 made for Allen Bradley with some extra features. You can program it to use multiple Ethernet addresses on the "outgoing" side and map them to DF-1/DH-485 node numbers to allow outgoing messages to multiple drops. But incoming packets are limited to a single device. In addition, I think the SLC suggestion is flat out wrong. It's a passthru, NOT a bridge. You won't be able to communicate to more than one device in the Ethernet to DH-485 route, and you can't pass through from DH-485 out onto the Ethernet port, only the other way around, because the SLC doesn't have a provision to supply which addresses to talk to. The Digi One IAP and probably the full Lantronix UDS-100 on the other hand are closer to true bridges. I haven't had much experience with the UDS-100 but with the IAP box, you can map everything in both directions and treat it as a true bridge. However, it is limited to a single device type so you can access all your PLC's even with RS-Logix this way as long as they are in the same family (all PLC-5's or all SLC's for instance) but you won't be able to access your Panelview's (if you have any) for instance. I've built DH+ bridges this exact same way. Ran with them for a couple years as we slowly made local connections to each PLC in turn under various projects and gradually eliminated the DH+ LAN. The best bridges are 1756-backplanes, but as you said, it's very expensive. A KF-2 or KF-3 and a Digi One IAP is much less expensive although it's slower. But it gets you an initial bridge until you can upgrade via sidecars or upgraded processors or adding additional IAP's directly to the Channel 0 ports until you can abandon your DH-485 LAN altogether.

[Mickey 71]

http://www.prosoft-technology.com/layout/s.../view/full/7487 http://www.protocolconverter.com/