A-B 1761-NET-ENI Module

Has anybody used the above module to connect an older fixed I/O SLC500 (part No. 1747-L40P or similiar) to an ethernet network?
The following is an extract from the user manual

Device Compatibility
The ENI is compatible with the following devices and applications:
· All MicroLogix, SLC, and PLC-5 DF1 Full-Duplex capable
controllers that have at least one RS-232 port
· Personal Computers using the RSLinx (V2.30.00 and higher) DF1
Full-Duplex Driver
· Other DF1 Full-Duplex compliant products that have at least one
RS-232 port, for example, operator interface devices
· RSLinx (V2.30.00 and higher) Ethernet Driver
· CompactLogix

I am looking at changing an existing DH-485 network to ethernet, using slc 500's, 5/01's, 5/02's etc. Has anybody had sucess with this type of retrofit??

ianingram said:

Has anybody used the above module to connect an older fixed I/O SLC500 (part No. 1747-L40P or similiar) to an ethernet network?
The following is an extract from the user manual

Device Compatibility
The ENI is compatible with the following devices and applications:
· All MicroLogix, SLC, and PLC-5 DF1 Full-Duplex capable
controllers that have at least one RS-232 port

Click to expand...

Notice it says "at least one RS-232 port"....

· Personal Computers using the RSLinx (V2.30.00 and higher) DF1
Full-Duplex Driver
· Other DF1 Full-Duplex compliant products that have at least one
RS-232 port, for example, operator interface devices
· RSLinx (V2.30.00 and higher) Ethernet Driver
· CompactLogix

Click to expand...

Notice it says DF1.......

RS-232 and DF1 just about rule out all but the SLC5/03, 5/04, and 5/05. The port on the older SLC's are strictly DH-485.

Maybe you could use a NET-AIC+ in conjunction with a NET-ENI.....not sure. I've never seen it done. It would be worth investigating.

It's not at all easy to bridge from DH-485 to Ethernet. The 1761-NET-AIC is just an RS-232/485 converter and isolator; it doesn't convert the token-passing DH-485 protocol into something asynchronous (DF1) or packetized (IP).

The SLC-5/05 allows some passthrough from Ethernet to DH-485, but so far I've been disappointed with the results. I keep on getting effects like broken browsing and Node 0 / Node 1 confusion.

In particular, the old 5/01 and 5/02 controllers did not support "off-link" messaging like the 5/03 does, so they cannot initiate messages heading off the local DH-485 network.

You might have some success with a 1747-KE module combined with a 1761-NET-ENI. That will allow you to convert DH-485 to DF1 protocol, then convert DF1 to Ethernet. What I don't know is how the addressing will come through.... I've not tried that combination.

In summary, you won't be able to just plug a DH-485 controller into a single converter box and put it on Ethernet. You may be able to bridge the old DH485 network to Ethernet with a separate module that first converts to DF1.

Thanks for your replys

I did overlook the fact that a rs-232 port is required
(& now feel like a dummy)

Has anybody tried to combine the 1747-KE module with a 1761-NET-ENI?

I haven't but to be honest with you if you to weigh the engineering costs and performance of swapping out a 5/03 with a 5/05 vs. the waste of time trying to get all of the odd-ball hardware to work it makes lots of $$$s and sense to do the processor swap.

Good Luck,

(8{)} ( .)

moartl said:

Has anybody tried to combine the 1747-KE module with a 1761-NET-ENI?

Click to expand...

Yes, I tried.

No, it doesn't work. The Net-ENI only works with one DF1 Full Duplex device, not with any kind of network bridges.

to (8{)} ( .)
Normally I would aggree with you, but the original poster talk about
"older fixed I/O SLC500 (part No. 1747-L40P or similiar)".

MOXA has a converter for Ethernet to Modbus RTU, but that's because Modbus RTU is very popular and an open standard free to use.
DH485 is not nearly as popular and is AB's propriatery and closed standard. So I dont think there will ever be an easy way to get DH485 to Ethernet.
If a ControlLogix can talk DH485, then maybe it would be possible (but costly). But I dont think that ControlLogix can talk DH485 (maybe via its serial port ?).

Mea Culpa

(8{)} ( .)