Issue

Looking for a setting to allow an instructions formal input parameters to be written to directly.

For example, the instruction TON has the name of it as TEST_TMR, the parameter TEST_TMR.PT can not be written directly to in the program without using an actual parameter connected to the input pin PT.

The same goes for counters, if there is a CTU and the name is TEST_CTU, the parameter TEST_CTU.PV can not be written to in the program to set the Preset Value.

When attempted, Control Expert produces the error message.

{MAIN : [MAST]}  :             (l: 41, c: 31) E1172 TEST_TMR.PT cannot be accessed

{MAIN : [MAST]}  :             (l: 41, c: 31) E1053 input variable 'TEST_TMR.PT' must not be assigned

Product line

Control Expert, Unity Pro

Resolution

Unlike the formal output parameters such as TEST_TMR.ET, the formal input parameters can only be written to internally from the Function Block as a matter of IEC  design requirements.

There is no setting to use that would allow it.

Released for:Schneider Electric Canada