AutomationDirect DL205 - Page 244

DL205 User Manual, 4th Edition, Rev. D
5-20
Chapter 5: Standard RLL Instructions
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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
DirectSOFT
A aaa
PD




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