Dear Everyone,

I have some issue with below code. I get from time to time negative value in the "Shift_M" Tag. Do you spot any error in the code. The script is execute at 14:00 to update "B14" and "B6" would have been read at 06:00 already in another similar script. So logically B14 > B6. 

Note: All Tag are PLC tags

Please Help me

Hello Experts,

Any help/suggestion please

Thanks

AutoGen_1725111

Do you try to make a taglogging of the tags so you can see the value in the moment when you do the sub?

Dear AutoGen_1725111

No, I do not do Taglogging but I monitor the Tags on PLC (VAT table) and also  the Tag value in Tag management. All seems normal values. The problem does not occur always. 

Murof

Hello farra

you are writing to a PLC Tag and then reading the same Tag again in the same script.

This could cause timing problems.

So you should use SetTagWaitXXX and GetTagWaitXXX, then the Script only runs a step further if the Tag value from or To PLC was set or readed

Bye Murof

 Dear Murof,

I thought so but is there any alternative . Somehow I do not want to use SetTagWaitXXX and GetTagWaitXXX. The call to these functions are not straightforward at least to me. 

Best Regards,

farra

 Solved 

Murof

Hello farra

you are writing to a PLC Tag and then reading the same Tag again in the same script.

This could cause timing problems.

So you should use SetTagWaitXXX and GetTagWaitXXX, then the Script only runs a step further if the Tag value from or To PLC was set or readed

Bye Murof

 Dear Murof,

I thought so but is there any alternative . Somehow I do not want to use SetTagWaitXXX and GetTagWaitXXX. The call to these functions are not straightforward at least to me. 

Best Regards,

I would read the values only once, do the calculations and then write back. Depends on how clean your scripts are running, you can use just a printf statement for debugging output, and open the apdiag window and leave it open in the background.