Siemens SINUMERIK 840D sl Function Manual page 55

System variable
$AC_IN_KEY_G_RUN_IN[1 ... 8]
1) As a result of the ANDlogic operation of the NC enable signal on the NC side in $AC_IN_KEY_G_ENABLE and PLC enable
signal NOT(DBX386.0 ... 7), the enable signal is formed in $AC_IN_KEY_G_ISENABLE and DBX390.0 ... 7.
2) The content of the system variable is transferred in the NC/PLC interface
3) The content of the NC/PLC interface is transferred in the system variable
Example
Inputs
● The main program starts a cycle (ZYKLUS_1), in which grinding is executed as well as the
intermediate dressing.
● An operator can request an "intermediate dressing" action asynchronous to the machining
operation itself using an input signal of the PLC I/O.
● Identifying the input signal and requesting the action is realized in a technology cycle.
Technology cycle ("SIGNAL_IN_x") is called in the action part of the synchronized action
(ID <xy>) set up in the cycle.
The call schematic, the relevant commands and the signal flow are shown in the following
diagram.
Synchronized actions
Function Manual, 08/2018, 6FC5397-5BP40-6BA2
NC/PLC interface DB21, ...
DBX387.0 ... 7
3.3 System variables for synchronized actions
Description
Enable request for the action on the PLC side (optional)
Detailed description
55