Diagnostics Of The Cpu 41X As Dp Master; Table 5-2 Meaning Of The "Busf" Led Of The Cpu 41X As Dp Master - Siemens SIMATIC S7-400 Manual

PROFIBUS DP
5.1 CPU 41x-3 PN/DP as DP master / DP slave
Startup of the DP Master System
Use the following parameters to set startup monitoring of the DP master:
● Transfer of the parameters to modules
● "Ready" message from the module
That is, the DP slaves must start up within the set time and be configured by the CPU
(as DP master).
PROFIBUS Address of the DP Master
All PROFIBUS addresses are allowed.
5.1.4

Diagnostics of the CPU 41x as DP master

Diagnostics using LEDs
The following table explains the meaning of the BUSF LED. The BUSF LED assigned to the
interface configured as the PROFIBUS DP interface will always light up or flash.
Table 5-2 Meaning of the "BUSF" LED of the CPU 41x as DP master
BUSF
Off Configuration correct;
All configured slaves can be addressed
Lit
Flashing
flashes CiR synchronization running
briefly
INTF lights up
briefly
5-6
Meaning
Bus fault (hardware fault)
•
DP interface fault
•
Different transmission rates
•
in multi-DP master mode
Station failure
•
At least one of the assigned
•
slaves cannot be addressed
Remedy
–
Check for short-circuit or
•
interruption of the bus cable.
Evaluate the diagnostics.
•
Reconfigure or correct the
configuration.
Check whether the bus cable is
•
connected to the CPU 41x or
whether the bus is interrupted.
Wait until the CPU 41x has
•
started up. If the LED does not
stop flashing, check the DP slaves
or analyze the diagnostic data of
the DP slaves.
–
S7-400 Automation System, CPU Specifications
Manual, 10/2006, 6ES7498-8AA04-8BA0