6
6-28
FM 351 Positioning Function Module
EWA 4NEB 720 6001-02
6.4 Functions which Read Data from the FM 351
All data which is to be read from a channel on the FM 351 is included in the
group of reading functions.
The reading of the check-back signals which is carried out by each FC is not
included.
In Table 6-8 you will find all the FCs which have read access to the FM 351
channels.
Table 6-8 FCs which Read Data
FC Name FC Task
DIAG_INF ... reads the complete diagnostic information made available by the
FM 351 in the event of a diagnostic interrupt.
ACT_DAT ...reads the current operating data.
In addition to the specific requirement, take note of the general requirements
quoted here for all FCs:
The function may only be called in the cyclic program.
Note
Only call read functions when you really want to read data. A complete, cy-
clic call of the read functions has the following effects:
Increase in the bus load.
Heavy load on the OB 1 cycle.
Heavy FM 351 load.
When using a number of channels the block must be separately called for
each channel.
The channel DB must be assigned the appropriate values.
The parameter IN_**** must be set to start the FC.
The FC must remain called until the parameter IN_**** is reset by the
FC.
Irrespective of their special task, all FCs read the check-back signals from the
FM 351 (for example, the current actual value). The read values are then en-
tered in the channel DB by the relevant FC.
Read Definition
Introducing the
FCs
Requirements
Task of all FCs
Programming the FM 351
To Next Page
Loading...
