Thunderstorms Wrecking PLCs

Have thunderstorms been damaging your factory's PLCs (Programmable Logic Controllers)? It happens every year and usually over the weekend. We get these calls all the time. They usually sounds like this: "We had a power outage over the weekend and now the PLC is in fault, can you send someone to help us out?" Our response is always, "Do you think you have a back-up of the PLC logic?"

We generally regard PLCs as nearly bullet proof, as they are designed for the factory floor and meant to hold up well, but they are not invincible. After programming faithfully for 10+ years, they seem to become more vulnerable at which the original designers and programmers may be long gone.

Here is a checklist for plant floor maintenance or operation personal to minimize exposure:

1. Back up your programs in multiple places
2. Make sure you have a laptop cable ready to connect to the old PC. (It may be a development tool that only runs on Windows 98 and requires a serial port. These are not as easy to come by as they once were.)
3. Make sure the code is commented and drawings are easy to find
4. Replace the backup battery in the actual processor
5. Protect your vital equipment with a surge protector or UPS
6. Consider upgrading to modern equivalent PLCs and development tools so we don't have to pull the 60+ year old guy/gal out of retirement to ask them what they did 15 years ago.

For additional information, fill out an "information request form" under the Contact Us section of our main menu.