Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 67)

Chapter 4
Data File Organization and Addressing
4–11
Data File 6 – Control
These are 3-word elements, used with Bit Shift, FIFO, LIFO, and Sequencer
instructions. Word 0 is the status word, word 1 indicates the length of stored
data, and word 2 indicates position. This is shown below:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0
1
2
Word
Length of Bit array or File
Position
Control Element Addressable Bits Addressable Words
EN = Enable
EU = Unload Enable (FFU,LFU)
DN = Done
LEN = Length
POS = Position
EN EU DN Internal Use EM ER UL
EM = Stack Empty (stacks only)
FD
ER = Error
UL = Unload (Bit shift only)
FD = Found (SQC only)
Bits labeled “Internal Use” are not addressable.
Assign control addresses as follows:
Format Explanation
R Control file
Rf:e f
File number. Number 6 is the default file. A file number between 10 – 255
can be used if additional storage is required.
: Element delimiter
e
Element
number Ranges from 0 to 255. These are 3-word elements. See
figure above.
Example: R6:2 Element 2, control file 6.
Address bits and words by using the format Rf:e.s/b
where Rf:e is explained above, and:
. is the word delimiter
s indicates subelement
/ is the bit delimiter
b indicates bit
R6:2/15 Enable bit
R6:2/14 Unload Enable bit
R6:2/13 Done bit
R6:2/12 Stack Empty bit
R6:2/11 Error bit
R6:2/10 Unload bit
R6:2/8 Found bit
R6:2.1 or R6:2.LEN Length value
R6:2.2 or R6:2.POS Position value
R6:2.1/0 Bit 0 of length value.
R6:2.2/0 Bit 0 of position value.