KEYENCE Visual KV Series - Manual (Page 33)

1.3 Device Configuration
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Chapter 1 Programming
1.3.4 Input Relays
Input relays receive ON/OFF signals sent from external input equipment.
Note 1: Input relays function as contacts in programs. They cannot be used as relay
coils (outputs).
Note 2: There is no restriction of the contact type (N.O. or N.C.) used, the order the
relay Nos. are used, or the number of relays used.
Basic unit
■ Input relay time constant
Though the time constant is usually 10 ms ±20%, it can be changed using the
following settings.
• When the HSP instruction is used: 10 µs ±20%
• While special utility relay 2813 remains ON, the time constant can be changed in
7 steps by setting data memory DM1940 as follows.
When DM1940 is set to 0: 10µs ±20%
1: 20 µs ±20%
2: 500 µs ±20%
3: 1 ms ±20%
4: 2.5 ms ±20%
5: 5 ms ±20%
6: 10 ms ±20%
Never set a numeric value of 7 or larger.
➮ For more about changing the input time constant, refer to "1.4.1 Input Time Constant Change
Function" (p.3-23).
■ Hardware input (independent of scan time)
•
High-speed counter
When the time constant is set to 10 µs using the HSP instruction or data memory
DM1940 (only while special utility relay 2813 remains ON), the maximum input
response of input relays 0004 and 0005 of CTH0 and CTH1 becomes 30 kHz.
• INT instruction: 0000 to 0003
This instruction can receive any signal without regard to the scan time as far as
the signal ON time is longer than the input time constant.
➮ "HSP instruction" (p.3-86), "INT instruction" (p.3-192), "4.1 High-speed Counter Instructions"
(p.3-204)
Note 1: While special utility relay 2813 remains ON, the input time constant can be
specified for all input relays in a basic unit.
Note 2: Never enter a number of 7 or larger to data memory DM1940.
Note 3: The input time constant specified by data memory DM1940 becomes
effective at the rising edge of special utility relay 2813. To change the input time
constant, first change data memory DM1940, then set special utility relay 2813 to
OFF and ON again. Or change the operation mode of a KV basic unit from PRO-
GRAM to RUN.
Note 4: If the HSP instruction and special utility relay 2813 are used at the same
time, priority is given to the HSP instruction.
Note 5: Only when a high-speed counter input or INT instruction is given, available
input signals do not depend on the scan time.
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