Hello,

I have a very strange problem with my user created code in SCL. Due file size, I uploaded the file in an URL. --Deleted Link--

I having problems with the code, so I look at it with debug. 

I have configured a VAR_TEMP variable called: "xABORT_SelfCheck of type BOOL as you can see.

When I read out the VAR_TEMP right after the block BEGIN, I see the value is TRUE?!? It should not be possible! 

After some testing, when I create a new VAR_TEMP of type INT called: "testtest", suddenly after compiling and downloading, the value of "xABORT_SelfCheck" is FALSE. 

Is this a serious bug in PCS7 (or at least SCL editor)?

PS: I also have another VAR_TEMP called: xErrorNum, when the INT "testtest" is not declared, the value is 5?!?. 

Very strange....

DayMark

Is this normal? I know a temp variable does have to be initialized each cycle, but shouldn't the values be FALSE for BOOLS and 0 for INTs when not initialized? 

So, you know then why don't you follow this rule?

Yes, it's normal. TEMPs must be always initialized, i.e. they must be always written before read.

Hello jacek,

In my program I have the following statement:

IF SelfCheck THEN x_ABORT_SelfCheck :=TRUE;

END_IF;

Further down I have statement:

IF Abort_CM OR x_ABORT_SelfCheck THEN QABORT :=TRUE;

END_IF;

This code works, but the x_ABORT_SelfCheck stays TRUE each cycle, so each cycle the QABORT is 1 

So, I quess this is an programming error of my part? I thought the VAR_TEMP looses it's value and each cycle is in the default state -> BOOL :=FALSE; But, it could be any value then...I quess..

DayMark

Hello jacek,

In my program I have the following statement:

IF SelfCheck THEN x_ABORT_SelfCheck :=TRUE;

END_IF;

Further down I have statement:

IF Abort_CM OR x_ABORT_SelfCheck THEN QABORT :=TRUE;

END_IF;

This code works, but the x_ABORT_SelfCheck stays TRUE each cycle, so each cycle the QABORT is 1 

So, I quess this is an programming error of my part? I thought the VAR_TEMP looses it's value and each cycle is in the default state -> BOOL :=FALSE; But, it could be any value then...I quess..

Best to keep to the rule <jacek d> spelled out.
Motivation ->

Think of TEMP as a scratch pad that all code blocks access; a common block of memory.

As user you have no control on how this memory is manipulated between code block calls. There is no assurances that you are accessing the same memory location. Different PLCs administrate the TEMP differently. If the TEMP block is 'zeroed' before each code block call, the PLC cycle would be badly effected.

DayMark

IF SelfCheck THEN x_ABORT_SelfCheck :=TRUE;

END_IF;

A little bit OT.

As x_ABORT_SelfCheck is a TEMP and if it's not written before this line, then better would be like this:

x_ABORT_SelfCheck:=SelfCheck;