Filter
Top Products
FX Series Programmable Controlers Applied Instructions 5
5-59
Operation 3 - Combined HSZ and PLSY Operation:
(Applicable units: FX
(2C)
and FX
2N(C)
)
Operation 3 allows the HSZ and PLSY instructions to be used to
g
ether as a control loop. This
operation is selected when the destination device (D) is assi
g
ned special M coil M8132. This
then allows devices (S
1
, S
2
) to be used to define a data table usin
g
(S
1
) as the head address
and (S
2
) as the number of records in the table - maximum number of records is 128. Each
record occupies 4 consecutive data re
g
isters (D throu
g
h D
+3
) proportioned in to two 32 bit data
areas.
The first pair of data re
g
isters (D,D
+1
) contain
the comparison value for use with the hi
g
h
speed counter. The second pair of data
re
g
isters (D
+2
,D
+3
) contain a value (from 0 to
1000) which represents an output frequenc
y
in
Hz. This value is loaded in to special data
re
g
ister D8132 when the comparison made b
y
the DHSZ instruction
g
ives a ‘TRUE’ output.
Special data re
g
ister D8132 can be used as the
source data for a PLSY (FNC57) output
enablin
g
the output to be varied with relative
count data.
As with Operation 2 onl
y
one record in the data
table is active at an
y
one time. The current
‘Record number’ bein
g
processed is stored in
data re
g
ister D8131. To observe the current
comparative value, data re
g
isters D8134 and
D8135 should be monitored as a double word
(32 bit) device.
Once the final entr
y
in the data table has been
processed, the operation complete fla
g
M8133
is set ON and the record counter (D8131) c
y
cles
back to the first record.
It is recommended that if the hi
g
h speed counter
and PLSY operations form a closed loop that
the last record entr
y
in the data table is set to K0
for the comparison value and K0 for the PLSY
output frequenc
y
. This will brin
g
the controlled
s
y
stem to a stop and the ‘Record number’
counter will not be able to c
y
cle back to the start
of the data table until the associated hi
g
h speed
counter is reset b
y
either pro-
g
ram or hardware
methods. This situation can be easil
y
monitored
b
y
checkin
g
the paired data re
g
isters D8134
and D8135 for the ‘0’ value.
It is recommended that the operation of the
PLSY instruction is dela
y
ed for 1 scan to allow
the DHSZ data table to be constructed on initial
operation. A su
gg
ested pro
g
ram usin
g
a pulsed
fla
g
is shown in the example on this pa
g
e.
0
1
Record
number
[D8131]
Comparison value
(lower/upper
register)
[D, D
+1
]
Output Frequency
For PLSY
Instruction
[D
+2
, D
+3
]
2
3
4
[D180, D181]
K40
[D184, D185]
K100
[D188, D189]
K400
[D192, D193]
K800
[D196, D197]
K0
[D182, D183]
K100
[D186, D187]
K600
[D190, D191]
K550
[D194, D195]
K40
[D198, D199]
K0
40
100
400
800
D8131
C251 - count value
equals HSZ
comparison value
C251 reset
M8000
K9999
M8132C251DHSZ D180
K5
C251
X17
100
600
550
40
PLSY Output Frequency in Hz
0
1
324
D8132, output value
in Hz for PLSY
instruction
M10
PLS M10
PLSY
D8132
K0 Y7
1
32
1
32