Siemens SINUMERIK 840D sl Function Manual page 1222

Detailed description
2.12 Block descriptions
2.12.24 FC 21: transfer PLC NCK data exchange
Description of functions
When the Transfer block is called, data are exchanged between the PLC and NCK according
to the selected function code. Data are transferred as soon as FC 21 is called, not only at the
start of the cycle.
The "Enable" signal activates the block.
FC 21 is processed only when "Enable" = "1".
The following functions for the data exchange between PLC and NCK are supported:
1. Signal synchronized actions at the NCK - channel
2. Signals synchronized actions from NCK - channel
3. Fast data exchange PLC-NCK (Read function in NCK)
4. Fast data exchange PLC-NCK (Write function in NCK)
5. Update control signals to NCK - channel
6. Update control signals to axes (data byte 2 of the user interface)
7. Update control signals to axes (data byte 4 of the user interface)
Declaration of the function
STL representation
VAR_INPUT
END_VAR
238
Enable :
Funct:
S7Var :
IVar1 :
IVar2 :
END_VAR
VAR_OUTPUT
Error :
ErrCode :
BOOL ;
BYTE ;
ANY ;
INT ;
INT ;
BOOL ;
INT ;
Basic logic functions: PLC Basic program powerline (P3 pl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0