Twido fail to auto run

[Foggers]

Hello,

I have several systems which have Twido TWDLMDA20DRT units in them. These are quite old, approx 10 years. On power up after a time off, the PLC fails to auto run. If I then cycle the power, they start up correctly. I'm leaning towards it being the internal battery being dead. Reportedly, the battery in these is "not replaceable", and it doesn't have facility for an external battery. Since the battery already seems defective, I cannot see what I am going to lose by replacing it.

Am I right in my thinking about the failure to auto run? What other problems would a dead battery cause?

Thanks very much

[FernandoRodrigues]

Hello @Foggers 
If I'm not wrong, the internal battery is required to store the previous status and then, return on it.
This status is not saved to the eeprom and for that, it returns on stop.
You could define an input as Run, connect to 24Vcc and check if behavior changes. That will confirm this suspect

Anyways, considerer to migrate to M221, where you can easily convert Twido project. Most cases are 100% converted.