DL205 User Manual, 4th Edition, Rev. B
5–20
Chapter 5: Standard RLL Instructions - Boolean
1
2
3
4
5
6
7
8
9
10
11
12
13
14
A
B
C
D
Positive Differential (PD)
The Positive Differential instruction is typically
known as a one shot. When the input logic
produces an off to on transition, the output will
energize for one CPU scan.
In the following example, every time X1 makes an off to on transition, C0 will energize for
one scan.
NOTE:
To generate a “one–shot” pulse on an on–to–off transition, place a NOT instruction immediately
before the PD instruction. The DL250–1 and DL260 CPUs support the STRND instruction.
STR
$
1
B
ENT
SHFT
CV
P
3
D
SHFT
0
A
ENT
C0
PD
X1
Handheld Programmer Keystrokes
Direct
S
O
FT
A
aaa
PD
þ
þ
þ
þ
230
240
250-1
260
Operand Data Type
DL230 Range DL240 Range DL250-1 Range DL260 Range
A
aaa
aaa
aaa
aaa
Inputs X
0–177
0–477
0–777
0–1777
Outputs Y
0–177
0–477
0–777
0–1777
Control Relays C
0–377
0–377
0–1777
0–3777
DS
Used
HPP
Used
