10
DEVICE EXPLANATION
10
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10.2 Internal User Devices
10.2.6 Edge relay (V)
10.2.6 Edge relay (V)
(1) Definition
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.
(2) Edge relay applications
Edge relays are used for detecting the leading edge (OFF to ON) in programs
configured using index modification.
* 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.
(3) Precautions
The edge relay of the same No. cannot be set in multiple steps of a program.
Figure 10.16 Edge relay
Figure 10.17 Application example and timing chart of edge relay
X0
X1
X10
V1
Edge relay
Stores the X0, X1 and X10
operation results
SM400
SM400
MOV K0 Z1
FOR K10
M0Z1
INC Z1
NEXT
Index register (Z1) clear
[Ladder example]
Repetition (10 times) designation
M0Z1 is turned ON 1 scan at
leading edge of X0Z1
Increment Index Register (Z1)
(+1)
Return to FOR instruction
X0Z1
1
V0Z1
1
X0 OFF
V0 OFF
M0 OFF
ON
ON
ON
X1 OFF
V1 OFF
M1 OFF
ON
ON
ON
[Timing chart]
When Z1=0
When Z1=1
1 scan ON at X1 leading edge
1 scan
1 scan
