DL205 User Manual, 4th Edition, Rev. D
5-161
Chapter 5: Standard RLL Instructions
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A
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D
In the following example, when X1 is on, the constant value (K6) is loaded into the accumulator
using the Load instruction. This value specifies the length of the table and is placed in the first
stack location after the Load Address instruction is executed. The octal address 1400 (V1400),
which is the starting location for the destination table and table pointer, is loaded into the
accumulator. The data source location (V1500) is specified in the Source to Table instruction.
The table pointer will be increased by “1” after each time the instruction is executed.
It is important to understand how the table
locations are numbered. If you examine the
example table, you’ll notice that the first data
storage location, V1401, will be used when
the pointer is equal to 0, and again when the
pointer is equal to 6. Why? Because the pointer
is only equal to 0 before the very first execution.
From then on, it increments from 1 to 6, and
then resets to 1.
Also, our example uses a normal input contact
(X1) to control the execution. Since the
CPU scan is extremely fast, and the pointer
increments automatically, the source data
would be moved into all the table locations
very quickly. If this is a problem for your
application, you have an option of using a one-
shot (PD) to move 1 value each time the input
contact transitions from low to high.
DirectSOFT
X1
Handheld Programmer Keystrokes
STR
$
SHFT
ANDST
L
3
D
SHFT
RST
S
MLR
T
MLR
T
PREV
1
B
ENT
6
G
0
A
0
A
ENT
SHFT
ANDST
L
3
D
1
B
4
E
0
A
ENT
0
A
1
B
5
F
0
A
ENTSHFT
LD
K6
LDA
0 1400
STT
V1500
Load the constant value 6
(HEX) into the the lower 16 bits
of the accumulator
Convert octal 1400 to HEX
300 and load the value into
the accumulator
Copy the specified value
from the source location
(V1500) to the table
V1401
XXX X
V1402
XXX X
V1403
XXX X
V1404
XXX X
V1405
XXX X
V1406
XXX X
V1407
XXX X
S
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