Siemens SIMATIC S7-300 Manual page 103

Principle of This function works together with a user DB. The DB number is passed when
operation
you call the FC with the DB_NO parameter.
Reading of the measured values MEASUREMENT_VALUES (in user DB
starting at address 60) is started when you set the in/out parameter IN_MSR
to one. The parameter is reset by the FC after the job is executed. The FC
must be called up until it has reset the in/out parameter. When the FM 354 is
used centrally, the Read job is processed within a single function-block cal-
lup. When the FM 354 is used in a distributed configuration, it may take sev-
eral function block calls to process the read job (only applies when called in
OB 1).
The in/out parameter remains set while the job is running. Data transfer is
complete when the in/out parameter is reset (IN_MSR = FALSE).
Error evaluation
Errors which occur are indicated in the binary result (BIE = 0).
Possible errors are:
Data transfer error during communication with SFC 59 "RD_REC". The er-
ror is returned in the output parameter RET_VAL (see reference manual Sys-
tem Software for S7-300/400; System and Standard Functions).
Example call
An example call is shown below in OB 1
in OB 1
STL
U DB_FM.CHECKBACK_SIGNALS.MSR_DONE;
FP FLANKENMERKER_MESSUNG_BEENDET;
S "ANSTOSS_LESEFKT";
CALL MSRMENT(
DB_NO := W#16#1,
RET_VAL := FEHLERCODE_LESEN,
IN_MSR := "ANSTOSS_LESEFKT");
U "ANSTOSS_LESEFKT";
SPB NWE;
UN BIE;
S FEHLER_LESEFKT;
NWE: NOP 0;
FM 354 Servo Drive Positioning Module
Programming the FM 354
.
Explanation
// "Measurement completed" checkback
signal
// Edge flag for "Measurement com-
pleted"
// Set initiation parameters
// CALLUP OF FC MSRMENT
// Initiation bit is still set
// Communication error
// Indicate error in Read function
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