MSG from CPX to ML1500 via NET-ENI

[vk_bt1]

Hi all, I've worked through messaging in both direction in the CPX and ML1100 with help from you guys. Which is much appreciated. I have a similar app, that requires it to be done to a ML1500 and CPX.

How does the NET-ENI affect this process? I had a cursorary look earlier in the week while at the workshop, establishing comms throught the NET-ENI for programming and monitoring was fairly transparent, but a couple of quick attempts at sending a message from the CPX to ML resulted in some kind of comms lockup that required a PLC restart.

Once again, I will need to send and recieve data from each respective PLC in this scenario.

Cheers.

 

[vk_bt1]

Anyone know what the path through the ENI into the CPx is. Thanks.

 

[vk_bt1]

Dont suppose any1 has some kind of working example? I don't have access to this gear at the moment, and would like to be prepared when the job is ready.

 

[Gil47]

Could you explain what is a CPx.?
A wild stab from me would be Compact Logix.

As long as RSLinx can see the Net ENI without a yellow triangle or red cross on it I believe the Net ENI will be transparent.

Do not try to make the Net ENI pass heaps of traffic if you want reliability, as they operate at serial speed not Ethernet.

 

[vk_bt1]

Hi, yes I was using CPx as an acronym for Compact Logix. The hardware setup seemed to be ok from memory, but setting up the Message statements was different to the CPx <--> ML1100 setup I had worked through previously. I didn't get much time to sort it, but I can recall it may have crashed the ML1500, or at least lost comms.

Also, by "...pass heaps of traffic..." how much would you quantify as heaps? We could have a slower tx / rx polling rate for those units, but there won't be huge amounts of data. Some process control stuff, and a few integers most likely.

 

[Ken Roach]

From the Ethernet side, a MicroLogix 1100 and a MicroLogix 1500 with 1761-NET-ENI appear identical.

When you configure a MSG instruction in a ControlLogix/CompactLogix processor, the MicroLogix will be an SLC-type target and the IP address of the MicroLogix is the endpoint. There are no CIP path segments past the Ethernet interface.

When you confiugure a MSG instruction in a MicroLogix equipped with a Net-ENI, the configuration is different from one with an integral Ethernet port.

There are two parts: the configuration of the 1761-NET-ENI and the configuration of the MSG instruction in the MicroLogix controller itself.

The important thing to understand is that the MicroLogix controller thinks it is using DF1 Full Duplex protocol. It knows about DF1 protocol and addressing only; it has no idea that there is an Ethernet connection out there.

The 1761-NET-ENI module has a table of DF1 Addresses = IP Addresses. You can set these up using the ENI Utility, or you can configure them by sending special messages to the ENI from the attached MicroLogix.

While the target DF1 address and target IP address are related only by this table, it is very common to make them similar; DF1 Address 12 is correlated with 192.168.1.12, and so on.

 

[Ken Roach]

There is a very key point on page 5-3 of the 1761-NET-ENI/ENIW User Manual (publication 1761-UM006).

DF1/IP table entries 0 through 44 are for sending messages to PLC-5E or SLC-5/05 or other MicroLogix controllers that have integral Ethernet ports. For these devices, the IP address is the endpoint of the CIP path.

DF1/IP table entries 45 through 49 are for sending messages to Logix family controllers, including CompactLogix. The end of the CIP Path is set to "backplane, Slot 0" when you use these table entries. This lets you send a message to a CompactLogix or FlexLogix controller, or to a ControlLogix controller that resides in Slot 0 of the backplane.

 

[Ken Roach]

Don't hammer the 1761-NET-ENI with messages; if you automatically re-trigger the MSG in the CompactLogix you might overwhelm the Net-ENI's limited processor.

Sending a message once a second should be very easy.

I always run the 1761-NET-ENI at a hard-set 19200 baud, 8/N/1 serial port configuration. I don't push for 38400 baud.

The 1761-NET-ENI is limited to 6 TCP connections at a time. 2 are reserved for Incoming connections, 2 for Outgoing connections, and 2 for either direction. So, if you point two PanelViews, a MSG instruction, and an RSLogix 500 session at the device, it's full up.

Be gentle with it, read the user manual, and it will work.

 

[vk_bt1]

Thanks for your Reply Ken and Gil, much appreciated. After actually having allocated some time, and having performed some design / programming, It has become apparent that our initial network comms model was uneccesarily complicated, ...... subsequently we are now adopting the CPLogix --> Micrologix only approach (read and write msg's in CPlogix). As per the suggestion made by several members of these forums, and in retrospect rightly so. ..... however ..... a lingering curiousity pushed me to make it work in both directions.

I have the msg timing CPx to ML1500 working off a one second timer pair. Doing the writes as the first timer times out, and the reads on the corresponding timer. two questions spawning from this:

1/ Should I be using a one shot, or does it already work off a transition?

2/ is the essentially 1 second write, 1 second read comms cyce ok?


I do have some other questions regarding INT's vs DINT's, and read write lengths, but I think I'll post that seperately not to muddy this subject too much.