Rockwell Automation 1747-PT1, D1747NP002 Hand-Held Terminal - Manual (Page 65)

Chapter 4
Data File Organization and Addressing
4–9
Data File 4 – Timers
Timers are 3-word elements. Word 0 is the control word, word 1 stores the
preset value, and word 2 stores the accumulated value. This is illustrated
below:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
0
1
2
Word
EN TT DN
Preset Value PRE
Accumulated Value ACC
Timer Element
Addressable Bits Addressable Words
EN = Bit 15 Enable
TT = Bit 14 Timer Timing
DN = Bit 13 Done
PRE = Preset Value
ACC = Accumulated Value
Internal Use
Bits labeled “Internal Use” are not addressable.
Assign timer addresses as follows:
Format Explanation
T Timer
Tf:e
f
File number. Number 4 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: T4:0 Element 0, timer file 4.
Address bits and words by using the format Tf:e.s/b
where Tf:e is explained above, and:
. is the word delimiter
s indicates subelement
/ is the bit delimiter
b indicates bit
T4:0/15 Enable bit
T4:0/14 Timer timing bit
T4:0/13 Done bit
T4:0.1 or T4:0.PRE Preset value of the timer
T4:0.2 or T4:0.ACC Accumulated value of the timer
T4:0.1/0 Bit 0 of the preset value
T4:0.2/0 Bit 0 of the accumulated value