What You Need to Know About Your PLC Software
If working on the hardware
is like being a surgeon, then dealing with software issues can seem like being a psychiatrist. Figuring out what’s gone wrong on the software is often difficult and there’s not a lot we can do to change that.
We can, however, mitigate the difficulties by dealing with PLC
software more routinely so it’s less likely to become its own issue.
Here are 3 ways you can make sure your software is “thinking” at its optimum levels so your 90-70 PLC stays healthy.
Diagnostic Fault Tables
The Controller Fault Table and I/O Fault Table are usually the first stop when there’s a fatal issue with a GE 90-70 system.
What you might be missing out on is that the fault tables are also a great resource to discover issues that aren’t fatal yet.
Discovering these faults before they are a major issue will keep your 90-70 running well.
Since not all faults are fatal, you may not have an indicator that something is wrong and the outward appearance is that things are running smoothly.
For example, the loss of an individual input or output is not fatal. Likewise, the informational and diagnostic faults in the tables can tell you if an analog input is over range, under range, or has an open wire.
These kinds of faults are not going to be immediately obvious, and may not affect the process right away, but can be just as problematic if left to worsen.
Reviewing the fault tables on a regular basis will help you find those mild concerns before they become big issues.
Watch this video
to see how to best use your fault tables as a diagnostic tool.
Back up Your Program
Like keeping up with the PM schedule, backing up the programs is something you know you should be doing. Far too many companies experience days-long stoppage when a simple software backup could have averted the situation.
You should be creating a backup every time you alter the program.
In addition to this simple rule, we’d like to add two follow-up rules that make a huge positive impact if you ever need to restore:
- Keep a second set of backups off-site. As a maintenance tech, you know first-hand that even the best-kept equipment can fail unexpectedly and spectacularly. Don’t trust your backups to a single laptop. Burn copies to disc or onto a thumb drive and keep somewhere safe.
- Keep several iterations. Having a backup of the current program is important, yes, but we also recommend that you keep all the different versions that have been used in production. It’s so much simpler to restore a “last known good” version of the program from backup than to revert manually!
You might be surprised to learn that the facilities most at risk with backups are those that rarely (if ever) update their programs.
Yes, they made backups when the programs were installed or last altered, but where are they stored. Maintenance techs
have come and gone in the intervening years, and now no one can find them.
Qualitrol is now offering Factory Risk Assessments where we will locate and verify backups for all of your GE 90-70 PLCs.
This includes ensuring you have the correct software on hand and installed for restoring programs to your specific processor.
If you would like to speak to someone about scheduling a free Factory Risk Assessment, please call 1 (800) 784-9385.
If you need help backing up or restoring your project, this video will help
Update When Available
Most of the newer software packages include the ability to sign up for email notifications of new updates. It is imperative that you sign up.
The manufacturer will let you know of issues they’ve uncovered and send you service packs to fix many common problems. Stay on top of them.
Otherwise, you’re apt to end up troubleshooting an error that could have been avoided.