Hello everyone,

I am working with an ABB PM582 controller (non-ETH version) that is connected to a PC via a CM577-ETH communication module. I am relatively new to ABB PLC systems, and after recently needing to replace the controller, I am encountering difficulties establishing a connection for configuration.

Most of the available documentation describes connecting to the PM582-ETH variant, but I have not been able to find info on how to connect to a standard PM582 through the CM577-ETH module.

I have already changed the PC’s IP address to match the factory IP settings of the PLC, and did everything documentation describes but no succsess. In Automation Builder, the CM577-ETH module is visible; however, there is no way to establish a connection to the controller itself.

I am certain that this setup is possible, as it was working previously with the same hardware.

Any help would be greatly appriciated

 

@ASEM.

Could it be that the CM577-ETH module was configured with a unique (different from the factory IP of the PLC) and perhaps that's why it's not possible to 'get through' the CM577-ETH module to the PM582 controller?

I presume you can PING the CM577-ETH module from the PC?

Admittedly I know nothing about the ABB582 (in any version/variant), I'm just trying to think about what might be causing the inability to get from the CM577-ETH to the PM582. I presume the CM577-ETH module has some possibly proprietary communication method to the PM582, hence the need for a CM577-ETH to communicate with the PM582 via Ethernet.

I also presume you are using the correct Ethernet cable (some older Ethernet cables were specially configured to allow direct communication with a PC). We don't know the age of the CM577-ETH module and what the cabling requirements are to communicate directly with a PC. Sometimes (in the "old days") without a special cable it was necessary to use a small Ethernet switch between the PC and a controller. My limited World Wide Web sleuthing indicates the CM577-ETH module has an internal Ethernet switch, but I don't quite understand why that's necessary--unless the CM577-ETH has the ability to have a unique IP address/subnet mask and the CM577-ETH module communicates via Ethernet protocol to the PM582 controller and the version/variant of PM582 doesn't have an Ethernet port so it requires a CM577-ETH module to interface between a PC and the PM582 using a UTP Ethernet cable/connection.

Sorry; that's all I have to offer. The documentation I found to CM577-ETH was extremely limited; perhaps the plant has a manual provided with the PM582 controller with some information about the CM577-ETH.

Best of luck! I see you've posted to other World Wide Web forums (at least one); please write back to let us know what you find.

 

@WTF?

Hello,

I've got problem solved by replacing the Ethernet module (CM577-ETH). After doing that and "updating objects" in Automation Builder software, I was able to establish connection successfully, simply making sure that PC and Controller are in the same sub-network.

The behavior of the previous module remains unclear. Although it was not possible to properly connect to the controller through the module, the CM577-ETH was still detected during a network scan in the software. Additionally, when I changed the controller’s static IP address directly on the physical unit, those changes were reflected in the scan results. This suggests that some level of communication was present, but not sufficient for proper operation.

Based on this, it appears that the module may have been partially damaged—still discoverable on the network, yet unable to function correctly.

Interesing case, never seen anything like that before

 

This is normal for the non-ETH PM582. You don’t connect to the CPU directly, the CM577-ETH is just a gateway. Make sure the CM577-ETH type, slot position, and PM582 firmware in Automation Builder exactly match the real hardware, then go online via the communication module. If it worked before, it’s usually a hardware config or firmware mismatch, not an IP issue.