The Busf, Busf1 And Busf2 Leds; The Busf Led Lights Up - Siemens SIMATIC S7-300 Hardware And Installation Manual

Testing functions, Diagnostics and Fault Elimination
Cross-reference
Details on the OBs and on SFCs required for their evaluation can be found in the
STEP 7 Online Help and in the Manual System Software for S7-300/400 - System
and Standard Functions.
Status and error display of DP-compliant CPUs
Table 11-5

The BUSF, BUSF1 and BUSF2 LEDs

LED
SF 5 VDC BUSF
On On On/ -
flashe
s
On On - On/
flashes
On On - X
Description of status X:
The LED can assume the status On or Off, but this status has no effect on the
current CPU function. For example, the states Force On or Off do not influence the
STOP status of the CPU
Table 11-6

The BUSF LED lights up.

Possible Errors
•
Bus fault (hardware fault).
•
DP interface error.
•
Different transmission rates in
multiple DP master mode.
•
If the DP slave interface is
active or there is a bus short-
circuit on the master.
•
For a passive DP slave
interface: baud rate search,
i.e. there are currently no
other active nodes on the bus
(e.g. a master)
11-10
BUSF1 BUSF2
- PROFIBUS DP interface error.
Remedy: Refer to the table below
X Error at the first PROFIBUS DP interface of CPU 318-2
DP.
Remedy: Refer to the table below
On/flash Error at the second PROFIBUS DP interface of CPU 318-2
es DP.
Remedy: Refer to the table below
response of the CPU
Calls OB 86 (when CPU is in
RUN mode). CPU switches to
STOP if OB 86 is not loaded.86
Description
•
Check the bus cable for short
or interruption.
•
Evaluate the diagnostic data.
Reconfigure, or correct the
configuration.
S7-300 Programmable Controller Hardware and Installation
Remedies
A5E00105492-02