Table of Contents
Advertisement
Programming the FM 453
6.3
FC RD_COM (FC 3) – Process Read Jobs Cyclically
Task
You can use FC RD_COM to execute read jobs. You must call
FC RD_COM once per channel in the OB 1 cycle.
The last read job must have finished processing, i.e. JOB_RD.NO in the user
DB (data byte DBB2) must have been cleared and status bit JOB_RD.DONE
enabled.
You initiate a new read job by entering the read job no. in JOB_RD.NO.
Do not include FC RD_COM in your user program if you do not process any
read jobs.
The FC performs the following action:
Executes the read job (JOB_RD) from the user DB, transfers the associated
data into the user DB, and displays the read job status.
Call Options
Description of
The following table describes the parameters of this FC.
Parameters
DB_NO
RET_VAL INT
Parameter types: I = input parameter, Q = output parameter
Principle of
This function works together with a user DB. The structure of the user DB
Operation
can be found in the library FMSTSVLI in data type
UDT 1. You need one user DB for each channel which contains entries for
addressing the FM 453 and the data for the individual functions of the
FM 453. The DB number is passed when you call the FC with the DB_NO
parameter.
6-14
Call in LAD Notation
(ladder diagram)
FC RD_COM
EN
DB_NO
RET_VAL
Name
Data
P
Type
Type
WORD
I
Q
Call in STL Notation
(statement list)
CALL RD_COM(
ENO
DB_NO
RET_VAL
Meaning
Data block number
Return code of SFC 59 "RD_REC"
FM 453 Servo Drive / Step Drive Positioning Module
C79000-G7076-C453-01
:= ,
:= );
Advertisement
Table of Contents
