Data Move Functions Shift Register - GE VersaMax PLC User Manual

Input/
Output
enable
IN
Length
ok
Instruction Set Reference
For public disclosure
10.3.3.1 Parameters of the Block Clear Function
Choices
When the function is enabled, the array is
flow
cleared.
IN contains the first word of the array to be
I, Q, M, T, SA, SB, SC,
cleared. The length of IN must be between 1
G, R, AI, AQ
and 256 words.
The number of words that will be cleared. This is
the length of IN.
The OK output is energized whenever the
flow, none
function is enabled.
10.3.3.2 Example
In the example, at powerup, 32 words of %Q memory (512 points) beginning at %Q0001
are filled with zeros. %Q is defined as WORD of length 32.
FST_SCN
| |
%Q0001

10.3.4 Data Move Functions Shift Register

The Shift Register function shifts one or more data words or data bits from a reference
location into a specified area of memory. For example, one word might be shifted into an
area of memory with a specified length of five words. As a result of this shift, another
word of data would be shifted out of the end of the memory area.
The reset input (R) takes precedence over the function enable input. When the reset is
active, all references beginning at the shift register (ST) up to the length specified for
LEN, are filled with zeros. If the function receives power flow and reset is not active,
each bit or word of the shift register is moved to the next highest reference. The last
element in the shift register is shifted into Q. The highest reference of the shift register
element of IN is shifted into the vacated element starting at ST. The contents of the shift
register are accessible throughout the program because they are overlaid on absolute
locations in logic addressable memory.
Enable
Reset
Value to be shifted
(first bit or word)
Description
IN
SHFR_
OK
WORD
Q Output
R
IN
ST
GFK-1503E User Manual 151