Help: S7 DI_STRNG issues

[John Kerin]

A colleague is currently trying to utilise the IEC command "DI_STRNG" in an application at the moment.

He needs to convert two different integers into strings, which then need to be concatenated.

The issue arises when we try to use a second instance of the "DI_STRNG". When the second one is added to the block, we are unable to download it.
Error =
* "Unable to copy the block" D21A
* "Incorrect local data length, or write protection encode fault" Message no. 294:6

We are using "symbolically defined" outputs (i.e. in the local variable table.)

Is it OK to use two instances of "DI_STRING"? or do they need to be dealt with in an indexed stack?

Any other ideas?

 

[L D[AR2P#0.0]]

Please post the source code (in absolute addressing format) of the block that will not download. What CPU are you using, how full is it ?

Sounds like your total local data area is too big.

As a test, create another (test) project and cut out as much as possible leaving only the problem block and only related blocks. Delete all blocks in the plc and then download the test project.