Migration error from step 7 to tia portal

Hi,

When programming an S7 PLC, there are rules for the use of block parameters within the block. One of them is "Output parameters may only be written". This is why you get the warnings even if it is possible to read the output parameters.

To tell you why you got an error for some parameters, we would need to see how your block interface is declared and how the program looks in the reported networks. However, you should change your programming to get rid of these errors and warnings.

Kind regards
Stefan

Hi,

Since you are using the "Set/reset flip-flop" instruction, the following part of the manual applies:

Note that the set and reset commands are dependent on the result of the logic operation. If the value of an output parameter is determined with these commands and RLO = 0, a value will not be generated.

While it may sound like you just need to be aware of this fact, the TIA Portal does not allow you to use it that way. You have to modify your program.

If you only get these errors for the flip-flops and you do not have a problem with getting a lot of warnings, the easiest way would be to use a temporary variable for the flip-flop and assign the output value to the previously used variable.

Be aware, however, that the behavior of a S7-1500 differs from that of a S7-300/400 regarding the use of a flip-flop for an output parameter. The better way would be to change the parameter type from output to in/out.

Kind regards
Stefan