Operation Manual EMGZ 490
15.12.2015
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The following graph (Fig. 7) shows the connection between FBs and DBs, respectively
how the access from FB to individual DBs is done.
Fig. 7: Connection between functional blocks and data blocks
E490013
7.6
Trigger Read-/Write-instructions
Proceed as follows to initiates a
Read-/Write-instruction
by the controller:
●
Read-instruction:
The index "FMS_ACYCLIC_DB." INDEX must be written to the
variable table of the SIMATIC Manager or in an application in the controller. Using a
one-time write trigger "FMS_TRIGGER_DB". READ_TRIGGER a read command can
be forced. The trigger is automatically reset. If the read command was successful,
the data of the index is stored in the DB "FMS_ACYCLIC_DB". VALUE_READ and can
be picked up from the variable table or the application
●
Write-instruction:
The index "FMS_ACYCLIC_DB." INDEX must be written to the
variable table of the SIMATIC Manager or in an application in the controller.
Moreover, the value "FMS_ACYCLIC_DB". VALUE_WRITE be set. Using a one-time
write of the trigger
„FMS_TRIGGER_DB“.WRITE_TRIGGER a write-instruction can be
forced.
The trigger is automatically reset.
