KEYENCE Visual KV Series - Manual (Page 36)

1.3 Device Configuration
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Chapter 1 Programming
1.3.7 Special Utility Relays
Each special utility relay has a unique function. By using special utility relays effec-
tively, programs can be simplified and program control improved.
Note 1: A special utility relay can be used as many times as desired in one program.
Note 2: Special utility relays dedicated for reading can be used as contacts, but
cannot be used as outputs.
➮ For more about relays dedicated for reading, refer to "1.3.8 Special Utility Relay List" (p.3-14).
Description
Relay 2002: Always ON
By setting an output relay to ON using relay 2002, the output relay can be used as a
"running indicator output".
Relay 2003: Always OFF.
Opposite that of relay 2002, use relay 2003 where it is not required to be turned on.
For example, when using only the up function of an up/down counter, use relay 2003
in the DW (down) input.
Relays 2004, 2005 and 2006: Clock pulse
For each relay, the time ratio is "ON:OFF = 1:1". (Accordingly, the ON time of relay
2005 is 0.05 sec/pulse.)
However, because these relays depend on the scan time, error as much as the scan
time is generated.
• By combining an output relay, an "intermittent output" can be made.
• By using relay 2006 as input for a counter, the counter can be used as a long-
term timer.
Relay 2007: Remains OFF during only one scan when operation is started.
This relay can be used when a signal needs to be sent after a specific period
(equivalent to one scan) after operation is started. This relay can also be used for
an initial reset at the start of operation.
After one scan, this relay remains ON.
2002
00000
LDA
DM0000
STA
2002
HSP
0100
Set the input time constant of relay 0100 to 10 µs.
Transfer the ON/OFF status data of channel 0000 to DM0000.
C000
1000 #03600
2006
C000
1000
1000 turns ON at every hour.
1000 #00100
0000
C005
2007
When operation is started, this relay returns
the current value of C005 to 0.
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