Posted 7 Sep 2015 Hello to all Since a certain time I've noticed that the parameters values sent to the plc via IHM are not anymore recognized by the plc I'm obliged to re-enter other parameter values to see the machine working fine again. The plc reference is: CJ1M CP 21 The IHM reference is NS10 What would be the problem,? Best regards. Share this post Link to post Share on other sites
Posted 7 Sep 2015 Does the PLC get turned of at all? Which memory area is storing the values? Is the battery in the PLC OK? Share this post Link to post Share on other sites
Posted 9 Sep 2015 Hello BobB, thank you for your reply The plc is turned off only during the week ends. The memory area used is DMxxxx I think the battery is ok because the "ERR/ALM" led is off Share this post Link to post Share on other sites
Posted 9 Sep 2015 Does the problem occur only when the PLC is powered off?? You might want to check all the references to those DM area registers in the program to see if they are being reset to some default value during power up. Share this post Link to post Share on other sites
Posted 9 Sep 2015 Yes - normally DM porblems are either a reset at start up using the start up flag or a dead battery. I assume it used to work OK at some point so probably not a reset at start up unless the code has been changed. I would replace the battery anyway - this should be done at the very least every 5 years. I have seen, in the past, the battery low detection not working. Try the battery. Share this post Link to post Share on other sites
Posted 10 Sep 2015 Hello the machine is working since 8 years now and I never had this problem.It's not a problem of code as there's no modifications in the programm. As stated by BobB, it's should be the battery although the low voltage battery is not detected. I'll change it and let you know; Thanks to all for your different posts Best regards. Share this post Link to post Share on other sites