communicate from PLC-5 to MLX 1100 via ethernet

hey guys, i am having a problem communicating to a mlx-1100 from a plc-5/40 with a enet sidecard. i believe i have everything set up right with my msg instruction but i keep getting error code 18 connection was broken. and i dont see the value change on n7:40 on the 1100. please help.

The PLC-5 used an older A-B Ethernet protocol called "CSPv4" that the MicroLogix and ControlLogix family don't support.

Try changing the message type to "Multi-Hop"; this switches the protocol to the modern EtherNet/IP.

Older PLC-5E controllers don't support "Multi-Hop"; RSLogix 5 should tell you if it's supported in your particular controller.

It says it doesn't support mulithop. Damn, do I have any other options?

Is it the plc that doesn't support the multi-hop or the sidecard? What would I need to upgrade if that's what it comes to..I believe the Plc is a plc-5/40E

Instead of using a Write Message from the PLC5, try setting up a Read from the ML1100. It is a newer PLC, and you may have better luck setting it up that way.

Stu....

It would be weird, but not impossible, to have a PLC-5E with a 1785-ENET sidecar. It's more likely that you have a conventional PLC-5 with a sidecar.

Firmware support has to be in both the PLC itself and in the sidecar. RA has the specifics in the Knowledgebase (Article ID 7983, Access Level Everyone) and it's been discussed here on the PLCTalk forum frequently.

Firmware upgrades in the PLC-5 controller are nontrivial; even for the ones that could be flash upgraded, RA no longer offers a field kit, but rather only upgrades processors as part of a remanufacturing service.

i guess were weird?

What you have is an ordinary PLC-5 "Enhanced" processor, part number 1785-L40B.

It has two DH+/RIO plugs, whereas the 1785-L40E controller replaced the #2 DH+/RIO plug with an Ethernet port.

The "E" is the Series letter... the current production PLC-5 controllers are Series F.

Controller firmware is identified by Series and Revision. Yours is Series E, Revision B.3, so it was built in late 1997.

You'd have to look at the 1785-ENET separately to determine its firmware revision.

Support for the EtherNet/IP CIP protocol began (according the KB article above) in version D.1 for the PLC-5 Series E controllers. Your controller will not be able to send or receive messages from a ControlLogix or MicroLogix controller over Ethernet without being upgraded.

If it's only one register you might consider an analog output to an analog input.

Also the serials ports configured for DF1 Half duplex Master/ Slave may work.

Mickey makes good points: I was addressing the specific question, not the follow-on questions.

You might be able to use a ControlLogix ENBT/DHRIO bridge do send this sort of message, add a 1761-NET-ENI to the serial port of the PLC-5 controller, or use DF1 over RS-232.