Modbus registers

[mark_automatedlogic 0]

Hello, Can anyone tell me how to extract or create a Modbus register list from a .flb file? I'm not a PLC guy - I'm a ALC tech trying to integrate to a GE PLC through a Modbus serial connection, and the PLC tech has given me the .flb file for the job. I can open it with WinZip, and there are files that seem to contain input and output register data, but I can't open them. Any help would be greatly appreciated. Thanks, Mark

[Steve Bailey 118]

The flb file is a VersaPro backup file. If you don't have VersaPro, contact me by PM. I'll give you an email address where you can send it to me. I can open it and print the variable list for you. None of the serial ports on a GE PLC are Modbus by default. Someone will need to configure a port as a Modbus slave. Furthermore, not all of the PLC's data will be available via Modbus. Someone may need to copy internal coils (%M memory) or analog outputs (%AQ memory) to memory areas that are accessible to Modbus.

[mark_automatedlogic 0]

Steve, Thanks very much for the offer, I will certainly take you up on that. The PLC was previously 'talking' to a Siemens automation system using Modbus, and we simply took over that port when we changed out their hardware for ours. I have verified that I can read random registers from the PLC, but I have no idea which registers contain the values that I need. I have asked the local rep for the list, but I have a feeling I'm pretty low on his priority list. I do appreciate the assistance, and will be in contact. Thanks again, Mark

[paulengr 44]

No, this is what GE refers to as customer service. Get used to it. Or better yet, avoid ALL GE products like the plague. GE has long ago decided that the main purpose of customers is revenue. Beyond that they serve no useful purpose. Oh, and engineers, programmers, designers, draftsmen, and the like are known as "overhead". They are not conducive to running an "efficient" business, whatever that means. Case in point, one of their HMI products had a well documented feature that an entire chapter of their manual (as well as their training books) spent time on. However, it didn't even work! After going through 3 levels of "customer service" at GE they admitted that it didn't work, and that I must be the only customer either using it or having problems with it, and that it was something that engineering was working on and they'd have a solution. This only took 6 weeks to get to this point. Well, about 18 months later, they contacted me to tell me that they had a patch to fix the problem. Needless to say, I had moved on quite a while ago. Those GE PLC's can talk Modbus but another annoying thing about it is that it is all buried in a "COMM Logic" block which is a block of data with a bunch of code numbers that you have to painstakingly configure to get it to work.

[Steve Bailey 118]

Paul, If you want to dump on GE, that's fine, but at least get your facts straight. This PLC port is a Modbus slave. As such it needs nothing more than to be properly set up in hardware configuration. No ladder logic required to support it. You

[lostcontrol 23]

Not to hijack this thread, but this wasn't the Portal product was it?