Siemens S7 - Function Blocks & UDT

Hi all,

im hoping that you can help me out on this problem.

I have a function block called "Valve_Control" (FB1), in this i have assigned a in/output variable as UDT0.

This works fine inside my function block but when i try to call the "Valve_Control" block i keep getting told my input into the UDT variable is invalid.

Basically i cant assign my UDT to the blocks UDT input variable,

Any ideas on how to get around this?

Ash

Sorry, i forgot to mention that im using step7 to program an S7-300 PLC

AshleyParr said:

Sorry, i forgot to mention that im using step7 to program an S7-300 PLC

Click to expand...

Maybe I misunderstood, but as I read it you have not declared the data you want to pass into the FB.
Today you just type UDT10 at the input to your FB?

That won´t work.

In a datablock, add a line and there you declare a new variable of type "UDT" and type in your UDT10.
This data you can now use to pass into your FB.

See this thread.
http://www.plctalk.net/qanda/showthread.php?t=43994&highlight=udt+step7

thankyou,

i had been trying to create a DB of a UDT & use that. And not create a DB a define the udt in there

Many thanks,

ash