Meaning Of The Busf Led Of The Cpu 31X-2 As Dp Master - Siemens SIMATIC S7-300 Series Reference Manual

CPU 31x-2 as DP Master/DP Slave and Direct Communication
Power-Up of the DP Master System
CPU 31x-2DP is DP Master
You can also set power-up time monitoring
of the DP slaves with the
"Transfer of parameters to modules"
parameter.
This means that the DP slaves must be powered up and configured by the CPU (as DP
master) in the set time.
PROFIBUS
Address of the DP Master
You cannot set the 126 as the PROFIBUS address for the CPU 31x-2.
2.4 Diagnostics of the CPU 31x-2 as DP Master
Diagnosis with LEDs
Table 2-1 describes the meaning of the BUSF LED.
For display the BUSF LED assigned to the PROFIBUS-DP interface is always it or
it flashes.
Table 2-1

Meaning of the BUSF LED of the CPU 31x-2 as DP Master

BUSF Description
LED off Configuring data OK;
all configured slaves are addressable.
S
LED on Bus fault (hardware fault).
S
DP interface fault.
S
Different transmission rates in
multiple DP master mode.
S
LED Station failure.
flashes
S
At least one of the configured slaves
cannot be addressed.
2-6
CPU 318-2 is DP Master
Using the parameters
"Transfer of parameters to modules" and
"Ready message from modules" you can
set power-up time monitoring for the DP
slaves.
Remedy
–
S
Check for bus cable breaks or short-circuit.
S
Evaluate the diagnostic data. Reconfigure or
correct the configuring data.
S
Check the bus cable connection to the
CPU31x-312, or check whether the bus is
interrupted.
S
Wait until the CPU 31x-2 has powered up. If the
LED does not stop flashing, check the DP
slaves or evaluate the diagnostic data for the
DP slaves.
PLC S7-300, CPU Specifications CPU 312 IFM to CPU 318-2 DP
A5E00111190-01