KEYENCE Visual KV Series - Manual (Page 49)

1.4 Special Functions
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Chapter 1 Programming
1.4.3 Constant Scan Time Mode
This function executes a program while keeping the scan time at a constant value
which usually changes based on the processing contents. This section describes
how to set this function.
Though the scan time changes usually depending on the processing contents, it can
be kept at a constant value by using this function. This function can be used to
acquire data from external equipment at a constant time interval.
The set value should be longer than the maximum scan time because the scan time
is kept at a constant value until the end of processing.
■ Setting procedure
Set the desired scan time to temporary data memory TM29.
Set special utility relay 2303 to ON.
The scan time is written to TM31.
The scan time can be set in 1-ms increments.
Enter the desired scan time (ms) to the temporary data memory.
■ Setting example
In this example, the scan time is kept at 20 ms.
Note 1: Be sure to set the constant scan time value so it is larger than the actual
scan time.
Note 2: If the actual scan time exceeds the set scan time, special utility relay 2304
turns ON (during the next 1 scan) while the actual scan time is written to TM28 (unit:
1 ms).
Note 3: The scan time can be set up to 200 ms in temporary data memory TM29. If
a value larger than 200 ms is input, it will be treated as 200 ms.
2008 2303
SET
TM29
STA
#00020
LDA
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