Message between ML1400 & 1756-L83 plcs

[EICS]

Can anyone screen shot an example message block
In a Control Logix PLC to communicate to a Micrologix 1400.

I tried this the other day and ended up with a hardware major
Fault, shutting down a production line.

My L83 CPU Firmware is at V28 and I would prefer the message to be in this processor.

I could not place the ML1400 in the tree for comms as it
Did not give me this option possibly unsupported ?
I tried to do it with comms path in the message, and this was where I crashed it.

Thanks in advance.

 

[JeremyM]

The MicroLogix doesn’t support Class 1 comms so you won’t be able to add it specifically to the tree. You could create a generic module with its IP, inhibit it, and use this as the message path.

The message type(s) are SLC typed read and write.

Path is either of:
a) L83E ethernet: 2, [IP Address of MicroLogix]
b) 1756-ENxT in rack: 1, [slot number of card], 2, [IP address of MicroLogix]

What fault was raised? I haven’t seen a bad path cause a crash before.

 

[EICS]

Hi Jeremy,


Thanks for the reply, much appreciated.


I did not take not notice of the Major error text (I really wish I had now in hindsight) to my horror of shutting down our production line I wanted to get it back up and running as fast as I could as it was extremely embarrassing.

 

[Ken Roach]

There is a way to inadvertently mis-configure SLC Typed Read instructions in Studio 5000 that will cause a "Major Non Recoverable Fault" in a 5580 series controller with v28, 29, or 30 firmware. If you create the MSG originally as a CIP Generic, then switch the type to SLC Typed Read, then the "Connected" and "Cache Connection" options stay turned on, rather than being disabled by default, which causes the MNRF.

The issue, and how to reconfigure the MSG control tag, is described in the RA Knowledgebase (Access Level: Everyone):

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/775825/loc/en_US#__highlight

 

[EICS]

Hi Ken,

Your knowledge is astounding. I went to site today as there was
A 4 hour Sunday afternoon shut-down window.

Well I crashed it again without consequence this time and I believe
What you have mentioned caused it as I did try this previously.

I have it working now as I made a few mistakes thinking
The format that the two in 2,xxx.xxx.xxx.xxx in path was the channel number, where as it relates to Ethernet comms.
I will post some screen shots in morning when I am back
For completeness so it may save someone else some heartache.

 

[EICS]

Here are some screen shots of successful comms between 1756-L83 CPU (V28) and Micrologix 1400 PLC


with the path 2,10.15.34.225 The Port 2 of the ML1400 is actually Channel 1, this is confusing


also attached is the Major Error fault Code

 

[ASF]

The "2" in your path does not refer to the micrologix, it refers to the ethernet port on your 1756-L83.

Msg instruction paths follow the pattern "port, address, port, address...". So a path between two Control Logix racks might look like: 1, 10, 2, 192.168.1.2, 1, 0

1 >> Out the "back door" of the processor, to the 1756 backplane (port 1)
10 >> To the ethernet module in slot 10 (address 10 in the chassis)
2 >> Out the "front door" of the ethernet module, onto the ethernet network (port 2)
192.168.1.2 >> to the ethernet module at that IP address (address 192.168.1.2)
1 >> Out the "back door" of the ethernet module, to the 1756 backplane (port 1)
0 >> To the processor in slot 0 (address 0 in the chassis)

In your case, you're simply going "out the front door" of your Control Logix processor using it's onboard ethernet port (port 2), and into the IP address on your micrologix.

 

[saultgeorge]

Here are some screen shots of successful comms between 1756-L83 CPU (V28) and Micrologix 1400 PLC


with the path 2,10.15.34.225 The Port 2 of the ML1400 is actually Channel 1, this is confusing


also attached is the Major Error fault Code

Hi perhaps this may help someone in the future. JesperMP posted this a few years back and I've kept it. This has gotten me out of a few situations, mainly because I don't do that much messaging and it is a good instructional tool. Hope this helps.

 

[EICS]

Thanks ASF & saultgeorge, this does clear it up, much appreciated.