Hi guys,

I feel like a *** here, i'm having the same problem on a 1511.

I'm trying to use a TON timer and it just won't start.

I tried to remove it and replace it with a new one, moving it to other locations, cyclic interrupts.

The exact same function works without a problem on a 1214C.

Any help would be greatly appreciated

Gilles

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Split from TON timer not working.

There really wasn't much code involved, during monitoring i could see the Bit m50.0 turn green but the timer would not start.

There wasn't any reset for this timer used in the program.

I worked around this problem by placing this timer in an FB instead of an FC.

Now it all works but i still have no idea why it wouldn't work in the first place.

Gilles

Hi.

There is some condition where trouble can slip in. The earlier firmware / software versions was also more prone for such behaviours.

The timer is started on an rising edge and cleared on a falling edge. Doing changes and downloads sometime disturb the internal flags of the timer instruction which causes such issues.

The DB linked to the FB is reinitialized for cases where structure changes were made. That mostly prevents the causes mentioned earlier.

The request from Hati is valuable: the online state of the instruction call may give an idea if the before mentioned is the case or there is some other issue. Please bare this in mind next time.

Regards.

Acknowledging the very good answer from mopS04.