KEYENCE Visual KV Series - Manual (Page 101)

Chapter 2 System Installation 1-77
1
2
Visual KV
Series
OK
OFF
ON
Scan time
OK
OFF
ON
Output of basic unit
OFF
ON
OFF
ON
800µs 800µs
Output of expansion unit
Receive
Communication cycle
in expansion unit
Receive Receive
Input signal
Incomplete receive
Scan time
Receive
Communication cycle in
expansion unit
Receive
Input signal
Incomplete receive
2.2 Connecting Visual KV Series Expansion Units
2.2.4 Transferring I/O Information between Expansion Units
and the Basic Unit
An expansion unit operates at a cycle of 800 µs without depending on the scan time.
When performing input while setting the input time constant of an expansion unit to
10 µs, or when synchronizing the output of a basic unit with the output of an
expansion unit, pay strict attention to the following contents.
When inputting
■ When the scan time is longer than 800 µs (communication cycle) plus 10 µs
(input time constant)
Set the input signal ON time equal to or longer than the scan time.
■ When the scan time is equal to or shorter than 800 µs (communication
cycle) plus 10 µs (input time constant)
Set the input signal ON time to 810 µs or longer.
In the case of output
The output of an expansion unit is delayed by a maximum of 800 µs from the output
of a basic unit.
When synchronizing the output of an expansion unit with the output of a basic unit,
pay strict attention to the communication cycle.
Note: When the output ON time is 800 µs or shorter, the output may be aborted.
KVHKA Chap 02.p65 08.3.11, 11:11 AM 77