Enet DH communication network questions

Hi all,

Can I have the HMI to be on two different networks, DH and Ethernet and have the Wonderware talk to devices on different networks at the same time?

Originally, I have the two micrologix 1100 PLCs (on the enet network) going thru a enet card in a controllogix gateway and route msgs via a DH card to a plc5 (plc5 is on the dh network with the HMI). I keep on getting communication problems with glitches, msgs from those two micrologx 1100 weren't getting to the plc5 100% of the time, some msgs are timed out because of the glitches. This is why I want to separate the ML 1100 out to be a enet network to talk to the HMI directly.

Has anyone experenced similar problems with the glitches? I thought it may be the terminating resistor problem, but it wasn't. Any suggestion is appreciated. Thanks.

Jeff

A better solution would be to have a ControlLogix gateway ...

A CLX chassis with a ENBT and a DHRIO card.

Connect the PC and the EtherNet PLC's to the ENBT, and the DH+ PLC's to the DHRIO module. This way you don't have to support the (P)KTX card in the PC.

Thanks for the suggestion. Have you ever expericed any glitches like I described in the first post? When I RSWho in RSlinx, those devices on DH network keep on showing on and off. Who could be the problem?

The msgs that I am sending from those two micrologix 1100 are some request bits that I need to send to the plc5 to have the logic in plc5 to determine what to do.

Thanks.

Your messaging problems could be on Ethernet, in the 1756-DHRIO, or on DH+, or in the firmware of the MicroLogix or the PLC-5. You don't know, and I can't guess without investigating the issue closely.

Ask your Wonderware rep if their communications drivers now support the MicroLogix 1100 on EtherNet/IP. The last time I investigated they did not.

Have you tried to gauge what percentage of your messages are getting through to the PLC-5 ? What kind of delay for retry are you looking at, and is it acceptable ?

When I RSWho in RSlinx, those devices on DH network keep on showing on and off.

Click to expand...

Take the time to diagnose and troubleshoot your DH+ network. Start with a call to your local Rockwell office or RA Tech Support and have somebody describe the DH+ Diagnostic Counters that are accessible from RSLinx to you.

Get an oscilloscope and examine the network waveforms (search this forum for examples).

When devices fail to respond to the simple polling of the RSWho utility (which is what those on-and-off icons mean), you very likely have a noise or installation problem on your network.