Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 140)

Chapter 8
Using Basic Instructions
8–21
Once instruction entry is complete, the parameters are condensed to two
screens as shown here:
P 0 0 0 R T O T 0 2
P 1 2 0 A 0
P 0 0 0 R T O B A S E
0 . 0 1 S E C
When the controller changes from the RRUN, RCSN, or RSSN mode to the
RPRG or FLT mode or user power is lost while the timer is timing but not
yet at the preset value, the following occurs:
•
Timer Enable (EN) bit remains set.
•
Timer Timing (TT) bit remains set.
•
Accumulated value (ACC) remains the same.
On returning to the RRUN, RCSN, or RSSN mode or when power is
restored, the following can happen:
Condition Result
If the rung is true:
TT bit remains set.
EN bit remains set.
ACC value remains the same and resumes incrementing.
If the rung is false:
TT bit is reset.
DN bit remains in its last state.
EN bit is reset.
ACC value remains in its last state.
Each Counter address is made of a 3-word data file element. Word 0 is the
status word, containing six status bits. Word 1 is the preset value. Word 2 is
the accumulated value.
CU CD DN OV UN UA Not Used
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Preset Value
Accumulator Value
CU = Counter Up Enable Bit
CD = Counter Down Enable Bit
DN = Done Bit
OV = Overflow Occurred Bit
UN = Underflow Occurred Bit
UA = Update Counter Accumulator Bit
Word 0
Word 1
Word 2
Word
Status
For high-speed counter instruction information, see chapter 14.
Counter Instructions
Overview