From TIA to Twincat

[Varri]

Hi!

Im looking at converting a machine program from Siemens TIA to Beckhoff Twincat. Most of it is SCL so its not a problem to convert the code.

On the Siemens part the program consists of FB`s and UDT`s for most things. Its a bit of work to convert this to codesys as i have to create a DUT for a stuct inside a DUT.

How can i most effectivly assign "start values" for a variable in a DUT, in the GVL?
Say i create a motor of type "motor", and i want the fallback to be these values:

Motor: motor := (spSpeed := 99,
speedLimitLow := 15,
speedLimitHigh := 85,
currentLimit := 25);

Next time im working on the machine, setpoints, limit values and scalings have changed from the HMI. Im TIA portal i could set the online values as start values, how can i do this in the Twincat?

 

[cardosocea]

Can't you do that as an FB_Init method of each FB?

 

[JesperMP]

Next time im working on the machine, setpoints, limit values and scalings have changed from the HMI. Im TIA portal i could set the online values as start values, how can i do this in the Twincat?

So what you are asking for is not how to declare start values, but how to take a snapshot of the actual values and import these into the PLC program as start values.

(I dont know Twincat, just wanted to clarify the question)

 

[busarider29]

You can create a DUT of type STRUCT and set all initial startup values there.

TYPE MotorStruct :
STRUCT
    spSpeed              :DINT:=99;
    speedLimitLow        :DINT:=15;
    speedLimitHigh       :DINT:=85;
    currentLimit         :DINT:=25;
END_STRUCT
END_TYPE

Is that what you're looking to do?

 

[JesperMP]

Im TIA portal i could set the online values as start values, how can i do this in the Twincat?

Is there a way to copy the online actual values to the offline start values ?
I think he is referring to the TIA functions 'snapshot' and subsequental 'copy snapshot to start values'.

 

[Levi G]

So what you are asking for is not how to declare start values, but how to take a snapshot of the actual values and import these into the PLC program as start values.

(I dont know Twincat, just wanted to clarify the question)

Perhaps with a recipe