Error Behavior; I/O Access Error; Module Fault; Read Diagnostics Data Of 3Wl / 3Vl - Siemens Library SENTRON 3WL Function Manual

3.1.5

Error behavior

Failure of the DP master or DP slave has already been determined by the previous
OB_DIAG1 block and evaluated by the RACKF, SUBN1ERR and SUBN2ERR inputs.
In the event of an error, the output OMODE features the identifier for "higher-ranking error"
(OMODE = 16#40xxxxxx).
3.1.6

I/O access error

From the viewpoint of the I/O configuration, 3WL / 3VL is a "compact" DP slave, i.e. it always
has a fixed I/O configuration. It can therefore be assumed that if an I/O access error occurs,
the entire DP slave must have failed (which is reported shortly afterwards).
I/O access errors are not evaluated any further, for this reason.
3.1.7

Module fault

Following a restart and when ACC_ID = TRUE, the module addressed with LADDR is
checked. SZL ID xC91 is read for this purpose. If the module addressed with LADDR does
not exist, the output QMODF is set and the identifier for "higher-ranking error" is entered for
the OMODE output (OMODE=16#40xxxxxx).
3.1.8

Read diagnostics data of 3WL / 3VL

If the 3WL / 3VL outputs a diagnostics alarm, system function RDSYSST (SFC51) will
activate reading of the device-specific diagnostics data.
The device-specific diagnostics data is also read out using the system function RDSYSST
(SFC51) following a CPU restart and rack start-up.
Since 3WL / 3VL following a Y link switches over to DPV0 mode, the device-specific
diagnostics data cannot be read.
The read information is transferred to the MOD_PAX0 block and the driver block where it is
evaluated.
It is also read if a request is output by the driver block at the "DIAG_REQ" input. This occurs
if:
● MAINT_MC ! = 0
● R_MAINT = 1
● Cyclically at DIAREQ_T ! = 0.0 min
The diagnostics data can also be displayed on a Maintenance Station (MS).
Library SENTRON 3WL / 3VL for SIMATIC PCS 7
Function Manual, 11/2008, A5E02316914A-01
Description of blocks
3.1 Diagnostics block DIA_WLVL
19