Question about BLKMOV instruction in STEP 7

[Aleksandra]

Hi everyone,

I have a short question about BLKMOV instruction, illustrated in the image below. I have the same piece of code in STEP 7 (ET200S) and TIA Portal (ET200SP).

In the first case, BLKMOV instruction doesn't allow me to put String data type as an output parameter, and in the case of TIA it does allow... variable at the "DSTBLK" assignment is an OUT variable of the FC.

I need this function in STEP 7, so - how to transfer string value from the temporary variable to the output variable (both of type String), if not with BLKMOV instruction?

Kind regards,

Aleksandra

 

[sigmadelta]

One way I can think if is to change your FC to an FB, and use a STAT for DSTBLK, and use the value from the instance DB.

Otherwise, you have to construct the pointer for #stringvalue (which would be the ANY datatype instead of STRING), and use #stringvalue for your DSTBLK - note: Make sure the specified length is the string length + 2 bytes.

Look up the topic "Using the Parameter Type ANY" in STEP 7 help.

 

[JesperMP]

Easier is to just do it in SCL.
Both in STEP7 Classic and in TIA will SCL encapsulate a lot of the fiddly stuff when copying data around.
In SCL, rather than calling BLKMOV, just write
#StringValue := #tempString ;