Siemens SIMATIC NET CP 442-1 RNA Equipment Manual page 31

INTF EXTF
(red) (red)
The behavior applies to BUS1F and BUS2F if there is no restriction listed in the "CP mode" column.
*)
The "MAINT" LED (yellow)
If the "MAINT" LED lights up, there is an error or an update is being performed in the CP.
Check the entries in the diagnostics buffer of the device.
CP communications status
Table 4- 3
LED
TXD (green)
RXD (green)
X1P1
X2P1 / X2P2
(green / yellow)
CP 442-1 RNA
Equipment Manual, 03/2022, C79000-G8976-C318-05
BUSxF RUN
(red) (green) (yellow)
*)
Meaning of the LED displays
LED display
STOP MAINT CP operating mode
(yellow)
Loading using the Firmware Loader is active.
The firmware download was aborted.
(STOP LED and RUN LED flash alternately)
Firmware is being activated.
- Module fault / system error
Meaning
CP sending over Ethernet.
CP is receiving over Ethernet.
Port has no connection over Ethernet.
Existing connection over port to Ethernet
LED flashes yellow (constant light green):
Port is sending / receiving via Ethernet.
Note:
Here, all received / sent frames are signaled separately for each
port.
Continuous data transfer via Ethernet at the port
LEDs
31