[?]: Why GetTagByte(GetTagChar("xx")) wont work?

[Janus]

Hello
i have I/O field and i need to get some tag value(in my case binary format).
Let say:

Code: Select all

Tag "motors"  --->   Text tag 8-bit character set
Tag "motor1"  --->   Unsigned 8-bit value
Tag "motor2"  --->   Unsigned 8-bit value
Tag "motor2"  --->   Unsigned 8-bit value

Tag "motors" store name of other tag (motor1 or motor2 or..etc.)
In I/O Field Properties > Input/Output > Output Value > Dinamic dialog> Expression i write GetTagByte (GetTagChar ("motors")).
And choose Direct.
The result is 0.
Why this expression wont work?
And is the any possibility to get this value.
P.S. When i choose I/O field with parameters GetTagChar ("motors"), everythink work perfect.
I get tag name. But how get tag value?

Wincc 6.2