MSG instruction address invalid

I have a network for a production line and we are receiving real time production data from the line sent to the servers.

The main PLCs on the line are all Control Logix and all have a network card for a common network. 3 of the machines have a Compact Logix processor so I’ve used a 1783-NATR to map the PLC address to a valid address on the network for the line. We’ve had an issue with 2 of the Compacts losing communication to the network. The why for that I’ve got figured out as well as the long term fix. The Compact for some reason loses the gateway address and once I re-install the gateway everything is fine.

I’ve programmed in handshaking between the PLCs (the engineer contracted by the company that did the initial network setup did not) and that has led me to today’s head scratcher. The 2 PLCs that I am having my gateway issue with can send a message through their NATR to the main communications PLC on the line network using the main line network PLC address (Identical machines 1769-L35E ver 17.004 called the east and west freezer). The third Compact doesn’t recognize any address path I give it to send a message through to the main communication PLC. (1769-L33ERM ver 21.11 the boxer PLC).

I can transmit to and read from the third PLC with instructions from logic in the main communications PLC so I do have handshaking working. I’ve also attached some network layout pics and the fault messages I get when I try to set up the MSG instruction in the boxer PLC.

Thoughts?

check the third for a subnet mask & missing gateway perhaps.

IIRC, the L3[25]E ethernet are implemented as a bridge, whereas the L33Es are not. Try removing the "1,0," from the beginning of your path.

Your network diagram shows the PLC enet as 192.168.1.2, but the NATR details shows 192.168.1.1. Just curious, as I've never used the NATR.

BachPhi said:

check the third for a subnet mask & missing gateway perhaps.

Click to expand...

BachPhi, subnet mask and gateway are present

clintm said:

IIRC, the L3[25]E ethernet are implemented as a bridge, whereas the L33Es are not. Try removing the "1,0," from the beginning of your path.

Your network diagram shows the PLC enet as 192.168.1.2, but the NATR details shows 192.168.1.1. Just curious, as I've never used the NATR.

Click to expand...

I just realized one of the pictures I uploaded was wrong. When I browse to get the PLC Ethernet path and then enter identical info for the balance of the path to match the other PLC's I get the error in the attached picture. As far as the PLC address in the NATR details, typo on my part when I copied and pasted from the Freezer network. The gateway on the Boxer is setup as 192.168.1.10 and communicates all other info on a read basis to the main PLC.

GOT IT! Thanks for your help!

I was thinking about what you said clintm about the L33's not being bridged and was staring at the picture I uploaded with the path DR2_Boxer, 2, 192.168.54.10, 1, 2, and realized the error message said Module could not be found.

I wondered if it meant the name DR2_Boxer was the module so I entered for the path "2, 192.168.54.10, 1, 2" because using a 2 denotes Ethernet communications and it worked perfectly. For some reason I guess the Ethernet port is part of the CPU and it doesn't like referring to itself, it just needs to know to look at the Ethernet port.

I appreciate your help, now I can go home and enjoy the rest of my Saturday.

Hey Geoff, just out of curiosity, why are you using MSG instead of produced/consumed tags? Its so much easier and all the handshaking is done for you. I've had to take the path you did when I need to communicate from CLX to SLC or Micrologix, but when it's all CLX, wouldn't just using tags be easier?

scarince said:

Hey Geoff, just out of curiosity, why are you using MSG instead of produced/consumed tags? Its so much easier and all the handshaking is done for you. I've had to take the path you did when I need to communicate from CLX to SLC or Micrologix, but when it's all CLX, wouldn't just using tags be easier?

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To be honest other than instances where we have processors in the same backplane I’ve never used produced and consumed tags. I’ve always done discreet messaging using MSG instructions. I was reading through the communications manual and saw notes on produced and consumed tags so now that you mention it I may investigate that further. Thanks for the info!