Hardware description
A.5 System resources
SIMATIC IPC BX-39A
100
Operating Instructions, 07/2022, A5E50715883-AA
A.5.2.2
Output register user LED L1/L2/L3 (read/write)
The "PC ON/WD" LED indicates the progress of the device startup by pulsing yellow/green.
Once the boot process is completed, the "PC ON/WD" LED lights up continuously green. The
"PC ON/WD" LED cannot be influenced.
The status of the user LEDs L1/L2/L3 can be read and written as follows.
Note:
Always use read-modify-write operations so that reserved bits are not overwritten. This
can lead to impairment of the functionality of the device.
Procedure
1.
Write 02h into the GPIO port select register (280h) to select the relevant register (GPIO2).
2.
Read or write the desired value from or to the GPIO2 data register (282h) to control the user
LEDs L1/L2/L3.
Meaning of the bits
User LED L1/L2/L3 register (read/write, address 282h)
Bits
Meaning of the bits
7
6
5
4
3
2
1
0
1
1
LED L1 / Run/Stop dark (default)
1
0
LED L1 / Run/Stop lights up red
0
1
LED L1 / Run/Stop lit green
0
0
LED L1 / Run/Stop lights up yellow
1
1
LED L2 / Error dark (default)
1
0
LED L2 / Error lights up red
0
1
LED L2 / Error lights up red
0
0
LED L2 / Error lights up yellows
1
1
LED L3 / Maint dark (default)
1
0
LED L3 / Maint lit red
0
1
LED L3 / Maint lights up green
0
0
LED L3 / Maint lit yellow
x
Reserved
0
WDT system reset: On
1
WDT system reset: Off
