Codesys 2.3, retain timer

[Lahotron]

Hi,

I'm using IFM CR0401 controller.
Can enyone explain me why my retain timer (TON), is set to true after power loss (doesn't hold old value, ET = PT).

I tried with very simple piece of test code.
Seems that test variable and counter hold their old values, but not the timer.

VAR RETAIN
test_timer: TON;
test_counter: CTU;
test_variable: BOOL;
END_VAR

test_timer(IN:= TRUE, PT := T#300s);
test_counter (CU := test_variable, PV := 10);

 

[gclshortt]

ET part of the TON instruction must be set to a variable.
Make this variable RETAIN.

http://www.parkermotion.com/manuals/Hauser/Compax3/CoDeSys_Manual_V2p3.pdf

https://www.youtube.com/watch?v=DB_1Legjl9g

Regards,

 

[shooter]

in addition to above, no need for the FB to be retain.

 

[ndzied1]

Are you trying to get the functionality of an Allen Bradley RTO instruction?

 

[Lahotron]

Thanks for replies.
I was confused because counter works fine as retain... why timer shouldn't.
My case is to count up time in a loop of 5 min, after power failure the timer should continue from the point before failure.
Solution looks like that:

VAR
  test_timer: TON;
  startup: BOOL := TRUE;
  set_time: TIME;
END_VAR

VAR RETAIN
  elapsed_time: TIME := T#0s;
END_VAR

IF startup THEN
  set_time := T#300s - elapsed_time;
  startup := FALSE;
END_IF

IF test_timer.Q THEN
  test_timer.IN := FALSE;
  set_time := T#300s;
ELSE
  test_timer.IN := TRUE;
END_IF;

test_timer (PT := set_time);
elapsed_time := test_timer.ET;

 

[shooter]

yep solution is good.