Siemens SINUMERIK 840D sl Commissioning Manual page 778

Dialog selection
9.2 Dialog selection using PLC hard keys
PLC interface
An area to select a hard key is provided in the PLC interface. The area is in
DB1900.DBB5003. Here, the PLC can directly specify a key value of between 50 and 254.
Acknowledgment by the operating software takes place in two steps. This procedure is
necessary so that the operating software can correctly identify two separate events if the
same key code is entered twice consecutively. In the first step, control information 255 is
written to byte DB1900.DBB5003. This defined virtual key activation enables the HMI to
identify every PLC key sequence uniquely. The control information is of no significance to
the PLC user program and must not be changed. In the second step, the actual
acknowledgment takes place with respect to the PLC by clearing DB1900.DBB5003. From
this point in time, the PLC user program can specify a new hard key. In parallel, the actual
hard key request is processed in the operating software.
Example
Selecting the "Machine" operating area:
1. PLC user program
2. Configuration file
\oem\sinumerik\hmi\cfg\systemconfiguration.ini
160
; PLC hard keys (KEY50-KEY254)
[keyconfiguration]
KEY50.0 = area:=AreaMachine, dialog:=SlMachine
KEY51.0 = area:=AreaProgramEdit
KEY52.0 = area:=AreaParameter
KEY53.0 = area:=AreaProgramManager
KEY54.0 = area:=AreaDiagnosis, dialog:=SlDgDialog,
cmdline:="-slGfwHmiScreen SlDgAeAlarmsScreen"
KEY55.0 = area:=Custom
KEY56.0 = area:=AreaStartup
KEY57.0 = area:=AreaStartup, dialog:=SlSuMDDialog
SINUMERIK Integrate Run MyScreens (BE2)
Programming Manual, 03/2013, 6FC5397-1DP40-3BA1