Edge Relay (V) - Mitsubishi Electric MELSEC-Q Series User Manual

10 DEVICES

10.2.6 Edge relay (V)

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(1) Definition
(a) An edge relay is a device which stores the operation results (ON/OFF
information) from the beginning of the ladder block.
Edge relays can only be used at contacts, and cannot be used as coils.
X0 X1 X10
(b) The same edge relay number cannot be used twice in program executed by
the Basic model QCPU.
(2) Edge relay applications
Edge relays are used for detecting the leading edge (OFF to ON) in program
configured using index qualification.
[Ladder example]
SM400
*1 *1
X0Z1 V0Z1
SM400
[Timing chart]
X0 OFF
V0 OFF
When Z1=0
M0 OFF
X1 OFF
When Z1=1 V1 OFF
M1 OFF
REMARK
1) 1: The ON/OFF information for X0Z1 is stored at the V0Z1 edge relay.
For example, the X0 ON/OFF information is stored at V0, and the X1
ON/OFF information is stored at V1.
V1
Edge relay
Stores the X0, X1 and X10 operation results
MOV K0 Z1
FOR K10
M0Z1
INC Z1
NEXT
ON
ON
ON
1 Scan
ON
ON
ON
1 Scan
MELSEC-Q
Index register (Z1) OFF
Repetition (10 times) designation
1 scan ON at X0 leading edge
Increment Index Register (Z1) (+1)
Return to FOR instruction
1 scan ON at X1 leading edge
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