Description of the device
1.3 LED display
SCALANCE M874, M876
Operating Instructions, 06/2015, C79000-G8976-C331-05
13
LED
Status
Meaning
L
OFF
Device turned off, no power supply.
ON
Device turned on, power supply present.
SC
OFF
SIM card OK, no connection.
ON
Wrong PIN number / SIM card error
ON
Connection established
Q
OFF
No reception
Signal strength: < -109 dBm
Flashing
Signal strength bad: -89 dBm to -109 dBm
On
Signal strength medium: -73 dBm to -89 dBm
ON
Signal strength good: > -73 dBm
OFF
No VPN connection is established.
ON
All configured VPN connections are established.
Flashing
Only some of the configured VPN connections are established.
P1/P2
OFF
Ethernet connection to local computer or LAN not established
ON
Ethernet connection to local computer or LAN established
ON
Device receiving / sending data
DI
OFF
Digital input inactive
ON
Digital input active.
DO
OFF
Digital output inactive
