Download 1775-6.4.1, PLC-3 Family Programmable Controller, Programming

Transcript
Chapter 5
Using Timers and Counters
Figure 5.11
Memory Storage for Counters
Data Table
O000
Output Image Table
Octal
Word
Address
O377
I 000
Input Image Table
I 377
T 0000
Timer Table
Decimal
Word
Address
T9999
ÉÉÉÉÉÉÉÉÉÉ
C0000
C0002
Counter Table
Up to 10,000 counters with each
counter consisting of three words
C9999
16–Bit Word
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
17
16
15
14
13
CU
CD
DN
OV
UF
12
11
10
07
06
05
04
03
02
01
00
RESERVED
1RANGE –32.768 – +32.767
Preset Word (CPRE)
1RANGE –32.768 – +32.767
Accumulated Word (CACC)
CU = Counter up enable bit
CD = Counter down enable bit
DN = Counter done bit
OV = Counter overflow bit
UF = Counter underflow bit
1Negative numbers stored in two’s complement form
5-14
Control Word (CCTL)