Siemens SIMATIC LOGO! CMR2020 - Page 20

Connectors and LED display
2.3 LEDs to display operation
LOGO! CMR2020 / LOGO! CMR2040
20 Operating Instructions, 09/2014, C79000-G8976-C356-01
Meaning of the LEDs
LED
Status
Meaning
All LEDs
Flashing
Fatal error
Lit
Firmware being updated
Not lit
• No voltage present or applied
• Device shut down
L
Power supply
Off
No external power supply connected
On
Power supply connected
Flashing
Initialization or reconfiguration active
P1
LAN
Lit green
Link
Part flashes yellow and
part lit green
Data
Off
No link or no cable connected
R
Signal strength (mobile wireless)
Lit green
Very good
Lit yellow
Medium
Off
No signal
Flashing
Data
F
Error
OFF
No error
ON
Error (see also "Error LED lights up red" (Page 132))