ryangriggs
Lifetime Supporting Member
Hello, I have inherited the job of maintaining about 10 SLC5/05 PLCs in a wastewater treatment plant, and along with them a laptop which is "supposed to" have the most recent versions of the programs.
We already learned that one program on the laptop is outdated, because one PLC lost its program and had to be re-downloaded. However, the code on the laptop did not include some modifications that had been made later, so we had to contact the last guy and get an updated version.
However, I am not sure about the other files on the laptop.
Before I start making any changes to the running code, or doing any type of maintenance on the units, I want to make sure I have an exact backup of the actual code running on the PLCs.
When I open RSLogix 500 and Go Online with one of these PLCs, I am prompted to select a file to use. When I select a file, it proceeds to go online and shows the running program.
However, I'm confused: does this mean the program on the laptop exactly matches the program on the PLC? or is RSLogix just using the symbol names and comments from the PC program and showing the logic from the PLC memory?
What would happen if the program in PLC memory differs from the one on the laptop, and how would I reconcile the two?
Sorry if this is a stupid question, and I appreciate any suggestions!
We already learned that one program on the laptop is outdated, because one PLC lost its program and had to be re-downloaded. However, the code on the laptop did not include some modifications that had been made later, so we had to contact the last guy and get an updated version.
However, I am not sure about the other files on the laptop.
Before I start making any changes to the running code, or doing any type of maintenance on the units, I want to make sure I have an exact backup of the actual code running on the PLCs.
When I open RSLogix 500 and Go Online with one of these PLCs, I am prompted to select a file to use. When I select a file, it proceeds to go online and shows the running program.
However, I'm confused: does this mean the program on the laptop exactly matches the program on the PLC? or is RSLogix just using the symbol names and comments from the PC program and showing the logic from the PLC memory?
What would happen if the program in PLC memory differs from the one on the laptop, and how would I reconcile the two?
Sorry if this is a stupid question, and I appreciate any suggestions!