Delta AH500 - Page 194

Chapter 5 Basic Instructions
5-15
Instruction code Operand Function
NED/ANED/ONED
S
1
, S
2
Starting the falling-edge
detection/Connecting the falling-edge
detection in series/Connecting the
falling-edge detection in parallel
Device
DX DY X Y M SM S T C HC D L PR
S
1
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S
2
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Symbol:
NED
S
1
：
Specified device Bit
ANED
S
2
：
For internal use Bit
ONED
Explanation:
1. NED/ANED/ONED corresponds to LDF/ANDF/ORF. The only difference between
NED/ANED/ONED and LDF/ANDF/ORF lies in the fact that users need to specify the bit
device S
2
in which the previous state of the contact is stored when NED/ANED/ONED is
executed. Please do not use the device S
2
repeatedly in the program. Otherwise, the wrong
execution result will appear.
2. The instruction ANED is used to connect the falling-edge detection of the contact in series.
3. The instruction ONED is used to connect the falling-edge detection of the contact in parallel.
4. Only when NED/ANED/ONED is scanned can the state of the device be gotten, and not until
NED/ANED/ONED is scanned next time can whether the state of the device changes be
judged.
5. NED/ANED/ONED only can be used in the function block.
Example:
1. The falling -edge detection of X0.0 starts, the falling -edge detection of X0.1 is connected in
series, the falling -edge detection of X0.2 is connected in parallel, and the coil Y0.0 is driven.
2. When both X0.0 and X0.1 are switched from OFF to ON, or when X0.2 is switched from OFF
to ON, Y0.0 is ON for a scan cycle.