GE VersaMax PLC, User Manual

Page: 151 / 318

10.3.3.1 Parameters of the Block Clear Function
Input/
Output
Choices
Description
enable flow
When the function is enabled, the array is
cleared.
IN
I, Q, M, T, SA, SB, SC,
G, R, AI, AQ
IN contains the first word of the array to be
cleared. The length of IN must be between 1
and 256 words.
Length
The number of words that will be cleared. This is
the length of IN.
ok
flow, none
The OK output is energized whenever the
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.
%Q0001
FST_SCN
| |
BLK_
CLR
WORD
IN
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.
Reset
OK Enable
SHFR_
WORD
R
Value to be shifted
Q
IN
Output
(first bit or word)
ST
Instruction Set Reference GFK-1503E User Manual 151
For public disclosure