Mitsubishi FX3UC SERIES User Manual page 169

FX Series Programmable Controllers
3UC
User's Manual - Hardware Edition
1) Calculation of overall frequency
The overall frequency is calculated using the above table according to the high-speed comparison
instructions being used in the program.
Overall frequency ≥ Sum of "response frequency of high-speed counter × Magnification for
calculation of overall frequency"
2) Example of calculation
When only the HSZ instruction is used six times in a program, the frequency is calculated by the formulas
shown in the "Only HSZ instruction" column in the above table.
High-speed counter No. to be
C237
C241
C253 (OP)
[
4 edge count
1) The overall frequency is calculated as shown below because HSZ instruction is used six times.
Overall frequency = 50 - 1.5 × 6 = 41kHz
2) The sum of the response frequencies of the high-speed counters used is
calculated as shown below.
"20kHz × 1[C237]" + "10kHz × 1[C241]" + "2kHz × 4[C253(OP)]" = 38kHz ≤ 41kHz
Input
used frequency
Operation as
20kHz
software counter
10kHz
Software counter
2kHz
]
5 Input Specifications and External wiring
5.5 High-speed Counters (C235 to C255)
Calculation of max.
response frequency
30 - 6(times) = 24kHz
30 - 6(times) = 24kHz
{30 - 6(times)} / 4 = 6kHz
Magnification
for
Instruction
calculation of
to be used
overall
frequency
×
1
HSZ instruc-
×
1 tion is used
six times.
×
4
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