Siemens CPU 31 Series - Status and Error Displays for CPU 31 x

Operating and display elements
2.2 Operating and display elements: CPU 31x
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
2-13
2.2.5 Status and error displays of CPU 31x
General status and error displays
Table 2-7 General status and error displays of the CPU 31x
LED designation Color Meaning
SF red Hardware or software error.
DC5 V green 5-V power for the CPU and the S7-300 bus
FRCE yellow LED is lit: Active force job
LED flashes at 2 Hz: Node flash test function (only CPUs with
firmware V2.2.0 or higher)
RUN green CPU in RUN
The LED flashes during STARTUP at a rate of 2 Hz, and in HOLD
state at 0.5 Hz.
STOP yellow CPU in STOP, or HOLD, or STARTUP
The LED flashes at 0.5 Hz when the CPU requests a memory reset,
and during the reset at 2 Hz.
Status displays for the interfaces X1, X2 and X3
Table 2-8 Bus error displays of CPU 31x
CPU LED designation Color Meaning
315-2 DP BF red Bus error at DP interface (X2)
BF1: red Bus error at interface 1 (X1) 317-2 DP
BF2: red Bus error at interface 2 (X2)
BF1: red Bus error at interface 1 (X1)
BF2: red Bus error at interface 2 (X2)
LINK green Connection at interface 2 (X2) is active
31x-2 PN/DP
RX/TX yellow Receive / Transmit data at interface 2 (X2)
BF1: red Bus error at interface 1 (X1)
BF2: red Bus error at interface 2 (X2)
BF3: red Bus error at interface 3 (X3)
LINK
1
green Connection at interface 3 (X3) is active
319-3 PN/DP
RX/TX
1
yellow Receive / transmit data at interface 3 (X3)
1
In the case of the CPU 319-3 PN/DP are located directly at the RJ45 socket (LEDs are not
labeled!)