Diagnostics Of A Cpu 41Xh Operating As Profibus Dp Master; Table 7- 2 Meaning Of The "Busf" Led Of The Cpu 41X Operating As Dp Master; Table 7- 3 Reading Out The Diagnostics Information With Step 7 - Siemens SIMATIC S7-400H System Manual

7.1.3

Diagnostics of a CPU 41xH operating as PROFIBUS DP master

Diagnostics using LEDs
The following table shows the meaning of the BUSF LEDs. Always the BUSF LED assigned
to the interface configured as PROFIBUS DP interface lights up or flashes when a problem
occurs.
Table 7- 2 Meaning of the "BUSF" LED of the CPU 41x operating as DP master
BUSF Meaning
Off Configuration correct;
all configured slaves are addressable
Lit
DP interface error

Different Baud rates in multi-DP master

operation (only in stand-alone mode)
Flashes
Station failure

At least one of the assigned slaves is not

addressable
Bus fault (physical fault)

Reading out the diagnostics information with STEP 7
Table 7- 3 Reading out the diagnostics information with STEP 7
DP master Block or tab in STEP 7
CPU 41x "DP slave diagnostics"
tab
SFC 13 "DPNRM_DG"
SFC 59 "RD_REC"
S7-400H
System Manual, 03/2012, A5E00267695-11
What to do
-
Evaluate the diagnosis. 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 powered up. If the LED does

not stop flashing, check the DP slaves or evaluate the
diagnosis of the DP slaves.
Check whether the bus cable has a short-circuit or a

break.
Application
Display the slave diagnosis as plain text on
the STEP 7 user interface
Reading slave diagnostics data,
i.e. saving them to the data area of the user
program
The busy bit may not be set to "0" if an error
occurs while SFC 13 is being processed.
You should therefore check the RET_VAL
parameter whenever SFC 13 was
processed.
Readout of data records of the S7 diagnosis
(saving them to the data area of the user
program)
7.1 CPU 41x–H as PROFIBUS DP master
See ...
See "Hardware diagnostics" in
the STEP 7 Online Help, and
Configuring hardware and
connections with
manual
For information on the
configuration of a CPU 41x, refer
CPU Data Reference
to the
Manual
; for information on the
SFC, refer to the
Standard Functions Reference
Manual
. For information on the
configuration of other slaves,
refer to the corresponding
description
System and
Refer to the
Standard Functions Reference
Manual
PROFIBUS DP
STEP 7 in the
System and
91