100
The high-speed counter is a ring counter and thus when its present count
value is incremented from 9999 to 0000, the completion flag of CNT 47 is
turned ON for one cycle. By using this flag as an input to the UP input of the
reversible counter (i.e., cascade connection) you can increase the number of
digits to eight. Although an ordinary counter can be cascade-connected to
the high-speed counter, programming is easier with CNTR since an ordinary
counter is decrementing.
II
DI
R
1813 (normally ON)
0002 (start input)
MOV(21)
#0000
DM 32
MOV(21)
#5000
DM 33
HDM(61) 47
HR 0
1813 (normally ON)
1906 (EQ)
0500
CMP(20)
CNT 46
#0002
CNT 47
1814 (normally OFF)
1810 (turns On for 1 cycle upon hard reset)
CNTR(12)
46
#9999
HR 000
Address Instruction Operands
0000 LD 1813
0001 MOV(21)
# 0000
DM 32
0002 MOV(21)
# 5000
DM 33
0003 LD 0002
0004 HDM(61) 47
HR 0
0005 LD CNT 47
0006 LD 1814
0007 LD 1810
0008 CNTR(12)
46
# 9999
0009 LD 1813
0010 CMP(20)
CNT 46
# 0002
0011 AND 1906
0012 AND HR 000
0013 OUT 0500
In the above program example, output 0500 is turned ON when the following
condition is satisfied (where S is the present count value of the high-speed
counter):
20,000 ≤ S ≤ 25,000.
In hard reset mode, program SR 1810, which turns ON for one cycle time
upon input of the hard reset signal, to CNTR as the reset input. Unless CNTR
and CMP are programmed immediately after the high-speed counter, the cor-
rect corresponding outputs may not be produced.
The high-speed counter is very useful in the following application. Here,
packages are being carried on a conveyor belt at random intervals. Some of
them are spaced far apart and others are clustered together, making it im-
possible to accurately detect and count them with photoelectric switches
alone.
By presetting the number of pulses generated when a single package is de-
tected and by counting those pulses, the number of packages can be accu-
rately counted, regardless of whether the packages are spaced or clustered.
Note
Packaging Machine
Timer and Counter Instructions Section 5-11
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