Technical data

Technology functions
CPU 317T: Technology Functions
6-232 A5E00251798-03
Output parameters
Parameter Data type Start value Description
Done BOOL FALSE TRUE: Command completed.
Busy BOOL FALSE TRUE: Command is busy
Error BOOL FALSE
TRUE: Command initiation
with error.
The command is not executed; the cause
is found in the ErrorID.
FALSE: Command initiation without error
ErrorID WORD 0
ErrorID of the Error output parameter.
Note
The runtime of command execution in the integrated technology plus the runtime of
the OBx cycle in which MC_WritePeriphery is called may lead to a considerable
length of reaction times. You should therefore connect the I/O requiring a quick
write access to the MPI/DP interface of your Technology CPU.
MC_WritePeriphery - Example
The example shown in the diagram shows the time-based relationship when writing
the I/O image DP(DRIVE).
The I/O image of outputs is written to the I/O via the position controller at the end of
each time slice for command execution. This write operation is carried out,
regardless whether the technology function "MC_WritePeriphery" is started or not.
"MC_WritePeriphery" is used to write the PLC data specified at input parameter
Data to the I/O image of outputs.
Write access to the I/O image of outputs is triggered by the positive edge at input
parameter Execute. Output parameter Busy is set fTRUE in time with this
operation. The MC_WritePeriphery command is added as new command to the
time slice of the first command execution cycle. Command execution is started
within this time slice. The second MC_WritePeriphery call reports completion of this
command (Busy is toggled to FALSE and Done is set TRUE).
At the end of the second command execution time slice, the most recently written
I/O image of outputs is written once again to the I/O via the position controller.
The DB update is triggered at the subsequent position controller cycle. The DB
update is interrupted within the time slice of the position controller, but is resumed
after this time slice has expired. The start of command execution is delayed due to
missing time gaps. The delayed command execution cycle is interrupted by the
next position controller time slice and by the subsequent IPO time slice.