Reading data from PLC5 to CLX

[Oceansoul]

I am trying to set up a msg read and write using a controllogix and PLC5.

All the MSG instructions will reside in the CLX. The CLX is on an ethernet network, which also has a ethernet/DH+ gateway (172.18.50.85). The gateway has 2 cards in a 4 slot chassis, slot 0 is ENBT, slot 1 is DHRIO. This gateway is connected to the DH+ network (CH B) which the PLC5 (node 22) is on.

I am having trouble writing out the address string in the MSG block in RSLogix5000. I know i need to go the IP of the gateway, then i get confused. Is it backplane (0), then DHRIO card (1), CH B (2), then the node of the PLC5 (22)? So 172.18.50.85, 0, 1, 2, 22 ?

 

[Ken Roach]

The CIP Path MSG instruction from the ControlLogix actually only goes as far as the DHRIO module itself.

The module then executes the function contained in the MSG on DH+, and returns the reply over the ControlLogix networks and backplanes.

That's why you designate the channel (A or B) and the target node, and whether it's Local or Remote. In your case if the PLC-5 is connected to Channel B with no other bridges or other devices in the way, it's Local.

Remember that CIP Paths are always pairs of numbers: the Port, and the Address.

Port 1 is the backplane, and Port 2 is the network port for any Ethernet or ControlNet module.

Starting from your ControlLogix, you need to navigate the CIP Path, where x is the slot number of the Ethernet card in the chassis with your ControlLogix.

1, x, 2, 172.18.50.85, 1, 1

1,x = Path to the Ethernet module in the chassis with your CPU.
2, 172.18.50.85 = Path to the Ethernet port of the remote Ethernet module in the "Gateway" chassis.
1, 1 = Path to the backplane and to the DHRIO in Slot 1.

 

[Oceansoul]

Thanks for the reply. I will try this when i get back in tomorrow. I was going wrong and trying to access the PLC within the CIP path, but now understand i only go as far as the DHRIO card and then the rest is set up in the next tab.