Siemens SINUMERIK 840D sl Function Manual page 1230

Detailed description
2.12 Block descriptions
7: Update control signals to axes:
The purpose of function 7 is to transmit important control signals at high speed in between
cyclic data transfers. The data byte 4 of application interface DB31 to DB61 is transferred to
the NC. The transfer is performed for all activated axes. This function can be used, for
example, to transfer a feed stop outside the PLC cycle.
The following signals are relevant:
Signal
Enable
Funct
S7Var
IVAR1
Error
ErrCode
246
Type Type Value range
I BOOL
I BYTE 7
I ANY S7 data storage area
I INT 0
A BOOL
A INT
Remark
1= FC 21 active
7: Control signals to axes
Not used
1: "Funct" invalid
Basic logic functions: PLC Basic program powerline (P3 pl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0