Automationdirect.com DirectLOGIC DL205 Series User Manual page 269

Chapter 5: Standard RLL Instructions - Timer, Counter and Shift Register
Shift Register (SR)
1
The Shift Register instruction shifts data through a
230
predefined number of control relays. The control ranges in
240
the shift register block must start at the beginning of an 8
2
250-1
bit boundary and use 8-bit blocks.
260
The Shift Register has three contacts.
3
• Data — determines the value (1 or 0) that will enter the
DS Used
4
HPP Used
• Clock — shifts the bits one position on each low to high
5
• Reset —resets the Shift Register to all zeros.
With each off to on transition of the clock input, the bits which make up the shift register
6
block are shifted by one bit position and the status of the data input is placed into the starting
bit position in the shift register. The direction of the shift depends on the entry in the From
and To fields. From C0 to C17 would define a block of sixteen bits to be shifted from left to
7
right. From C17 to C0 would define a block of sixteen bits, to be shifted from right to left.
The maximum size of the shift register block depends on the number of available control
8
relays. The minimum block size is 8 control relays.
Operand Data
Type
9
A/B
Control Relay C
10
DirectSOFT
X1
11
X2
12
X3
13
14
Inputs on Successive Scans
Data
A
B
C
D
5–52
DL205 User Manual, 4th Edition, Rev. B
register
transition
DL230 Range
aaa bbb
0-377 0-377
Data Input
SR
From
Clock Input
To
Reset Input
Clock Reset
1 1 0
0 1 0
0 1 0
1 1 0
0 1 0
0 0 1
Indicates
ON
DL240 Range DL250-1 Range
aaa bbb aaa
0-377 0-377 0-1777
Handheld Programmer Keystrokes
$
STR
$
STR
C0
$
STR
S
SHFT
C17
RST
B
1
Shift Register Bits
C0
Indicates
OFF
SR
DATA
From A
CLOCK
To
RESET
DL260 Range
bbb aaa
0-1777 0-3777
B
ENT
1
C
ENT
2
D
ENT
3
R
SHFT SHFT
ORN
H
ENT
7
C17
aaa
B bbb
bbb
0-3777
A
0