PLC system backups - Are yours up to date?
PLC systems in general are extremely reliable, and in many cases there has never been any need to reload or edit a PLC systems program. Most companies maintain regular backups of all PLC programs. However, I have encountered many situations where a system has developed a problem that required the program to be reloaded, and no backup has been available.
Without a reliable backup, what are the options?
- Contact the company that originally built the system. This option can be a dead-end, if the company no longer has a backup, or the company no longer exists. Maybe the system was built overseas?
- Reprogram the system from scratch. This can take a long time and requires a detailed functional description, coding, testing and recommissioning. This means a long period out of service, and costs quickly escalate.
What can you do to avoid this?
While the system is running properly, check that you have complete and up-to-date documented program backups. If not, make contact with the equipment manufacturer or the system integrator who programmed the system. If this proves unsuccessful, have someone take a backup of the system, and store the backup in a safe place. The small cost and effort put in to do this could save lots of headaches and loss of production in the future.
System maintenance and future requirements
Having reliable program backups are invaluable when fault-finding or making changes to a system. If there are problems with a system, fault finding is much easier if a documented backup of the program is available. Also, at some stage the system may need to be upgraded because the hardware has become obsolete, replacement parts are hard to get, or there is a need to improve or expand the system. An up- to-date and documented backup of the system greatly reduces the effort of upgrading or modifying.
Last Thoughts.
Operator panels (HMI) are another area that are often overlooked when it comes to backups. In some cases, even backing up a running HMI presents problems. Often no HMI can mean the system cannot be used.
So, plan ahead. Make sure you have the best possible backups, and reduce costly down-time.
