i want to know what is the effective diffrence between STRUCT datatype and UDT datatype.

as both of them can have the same structure.

Each of the conveyors' control variables will have this structure. If you decide that the command bits should have "standby" under the list, then there is only one place to change that deffinition.

I hope this is of help.
w

Late note:
Under TIA it is possible to use the MOVE function to copy one structure to another. Maybe this can be done under Step7 V5.5 also.

Example..
[deffinition]
conveyor_1 : "conveyor_control";
conveyor_2 : "conveyor_control";

[code]
conveyor_2 := conveyor_1;

w

............................

mohamed elokby