User manual

8-8
Distributed I/O System DP/ASi Link
EWA 4NEB 710 6055-02b
At this point you will find a brief example of how to read the slave diagnosis
into your PLC using FB IM308C.
The following assumptions apply to this STEP 5 program:
 The IM 308-C is assigned, as a PROFIBUS-DP master, pages 0 to 15
(number 0 of IM 308-C).
 The station number of the DP/ASi link is 3.
 The slave diagnosis is to be stored in DB 30. You may also use any other
data block to store it in.
 The slave diagnosis consists of 26 bytes.
AWL Explanation
:A DB 30
:SPA FB 192
Name :IM308C
DPAD : KH F800
IMST : KY 0, 3
FCT : KC SD
GCGR : KM 0
TYP : KY 0, 20
STAD : KF +1
LENG : KF 26
ERR : DW 0
Default address area of the IM 308-C
IM No. = 0, DP/ASi link No. = 3
Function: Read slave diagnosis
Not evaluated
S5 data area: DB 20
Diagnostic data, from data word 1 on-
ward
Length of diagnosis = 26 bytes
Error code stored in DW 0 of DB 30
The DP/ASi link can send two different diagnostic messages:
 Dynamic diagnostics
If a new fault occurs on the DP/ASi link, the diagnosis is fetched auto-
matically by the DP master.
This procedure is repeated every time the diagnosis is modified.
 Static diagnostics
The DP/ASi link uses static diagnostics when the ASi power fails. While
static diagnosis is enabled, the DP master requests diagnostic messages
from the DP/ASi link.
Neither input nor output data are exchanged between the DP master and
the DP/ASi link during this period.
Static diagnostics is retained until you have remedied the reason for the
failure for the diagnostic message.
If there is no longer a reason for a diagnosis, the DP/ASi link sends a final
diagnostic message without any further error messages.
Example
Diagnostic status
Fault remedied
Diagnostics and Error Handling