3 . I n s t r u c t i o n S e t
M N050 03003E F or mo re infor ma tio n vi sit:
w w w. e a t o n . c o m
3-271
API Mnemonic
Operands
Function
91
LDF
S
Falling-edge Detection Operation
Bit Devices
Word devices
Program Steps
Type
OP
X Y M S K H KnX KnY KnM KnS T
C D E
F
S * * *
*
*
*
LDF: 3 steps
ELC ELCB
ELCM
PB PC/PA/PH
PV
PB PH/PA
32 16
P
32 16
P
32 16
P 32 16 P 32 16
P
Operands:
S
: Bit address
Description:
The LDF instruction is similar to the LD and LDP instructions, but LDF requires a true-to-false
transition of
S
to be energized for one program scan. Then, the state of
S
must go true, then false
again to be energized.
Program Example:
Ladder Diagram:
X0
X1
Y1
Instruction:
Operation:
LDF
X0
; Start X0 falling-edge detection
AND
X1
; Series connection A contact of X1
OUT
Y1
; Drive Y1 coil
Points to Note:
1 If specific rising-edge contact state is ON before ELC is powered, the rising-edge contact
will be True after power is applied to the ELC
2 If X1 is ON and X0 transitions from ON to OFF, Y1 will be energized for one program scan,
then it will turn OFF. Y1 will not turn on again until X0 goes ON, then OFF again. .
Содержание ELC-PB
Страница 1: ......
Страница 5: ...For more information visit www eaton com MN05003003E iv...
Страница 29: ...ELC Programming Manual For more information visit www eaton com MN05003003E 1 24 MEMO...
Страница 502: ...3 Instruction Set MN05003003E For more information visit www eaton com 3 333...
Страница 601: ...ELC Programming Manual For more information visit www eaton com MN05003003E 3 432...
Страница 625: ...ELC Programming Manual For more information visit www eaton com MN05003003E 3 456...