Edge Relay (V); Step Relay (S) - Mitsubishi Electric MELSEC iQ-R Series User Manual

Edge relay (V)

The edge relay is a device that memorizes operation results (on/off information) from the head of the ladder block, allowing its
use only by the EGP/EGF instruction. This device is executed for various objectives such as the rising (from off to on)
detection in the structured programs by the index modification.
SM400
*1 *1
X0Z1 V0Z1
SM400
*1 Edge relay V0Z1 memorizes on/off information of X0Z1.
X0
OFF
V0 OFF
Z1 = 0
M0 OFF
X1 OFF
OFF
V1
Z1 = 1
M1 OFF
(1) When X1 is rising, this device is turned on for one scan duration.

Step relay (S)

This device is used when specifying SFC program steps. This device is also used when specifying step No. through such
methods as verifying (monitor, current value changes) SFC programs with SFC control instructions or the engineering tool.
( MELSEC iQ-R Programming Manual (Program Design))
This device is designed only for SFC programs, and cannot be used as a substitute for an internal relay in a
sequence program. If it is used, an error may occur, causing a system failure.
27 DEVICES
456
27.3 User Device
MOV K0 Z1
Clear the index register (Z1).
Specify the number of repeats
FOR K10
(10 times).
Turn on M0Z1 for 1 scan by the
M0Z1
rise of X0Z1.
Increment (+1) of the index
INC Z1
register (Z1)
Return to the FOR instruction.
NEXT
ON
ON
ON
1 scan
ON
ON
ON
1 scan
(1)