Configuring Hardware and Communication Connections STEP 7.pdf

Configuring the Distributed I/O (DP)
Example 2: Evaluation of Diagnostic Data in OB 82 with SFB 54 "RALRM"
The target area for diagnostic data must be large enough to hold standard
diagnostics (6 bytes), identifier specific diagnostics (3 bytes for 12 slots) and the
evaluation of device-specific diagnostics (module status only, which requires 7
more bytes).
Extended evaluation (channel-specific diagnostics) would require the reservation of
additional bytes, provided the DP Slave supports this function.
// ...
// ...
L 120 //determine the start address for the
//module/station,
T "Slotadresse_Diag" //from which the diagnosis is to be
//fetched
CALL "RALRM" , "DB54"
MODE :="Alle_Params" // 1 = all output parameters are set
F_ID :="Slotadresse_Diag" //start address of the slot from
//which the diagnosis is to be fetched
MLEN :=20 //max. length of diagnostic data in bytes
NEW :="neu" //irrelevant
STATUS:="RET_VAL" //function result, error message
ID :="Slotadresse_Alarm" //start address of the slot from which an
//interrupt was received
LEN :="Laenge_Alarminfo" //length of the supplementary interrupt
//info (4 bytes header info+16 bytes
//diagnostic data
TINFO :=P#M 100.0 BYTE 28 //pointer for OB start info + management
//info: 28 bytes as of MB 100
AINFO :=P#M 130.0 BYTE 20 //pointer to the target area in which the
//diagnostic data is to be stored
// ...
//Structure of the stored diagnostic data:
// MB 130 to MB 133: header info (length, identifier, slot)
// MB 134 to MB 139: Standard Diagnostics (6 bytes)
// MB 140 to MB 142: identifier specific diagnostics (3 bytes)
// MB 143 to MB 149: module status (7 bytes)
// ...
U M 141.0 //slot 1 error?
SPB stp1
BE
stp1: L MB 147 //fetch module status slots 1 to 4
UW W#16#3 //filter slot 1
L W#16#2 //2-bit status 'wrong module',
//wrong module inserted
==I
S A 0.1 //reaction to wrong module
//..
L MB 147 //fetch module status slots 1 to 4
UW W#16#3 //filter slot 1
L W#16#1 //2-bit status 'invalid data',
//invalid user data
==I
S A 0.2 //reaction to invalid user data
Configuring Hardware and Communication Connections with STEP 7
3-64 A5E00706939-01