Mitsubishi Electric MELSEC Q Series User Manual page 206

(b) Calculation of auto refresh time
The automatic refresh time of the CPU shared memory is calculated in the following equation.
1) For Basic model QCPU
(Auto refresh time)
= (N1 + (No. of transmission word points)
(N3 + (No. of other CPUs)
• The number of received words is the sum of the numbers of words transmitted by the other CPUs.
• For N1 to N5, use the values in Table5.3.
Basic model QCPU
Q00CPU
Q01CPU
2) For High Performance model QCPU/Process CPU
(Auto refresh time) = (N1 + (No. of reception word points)
• The number of received words is the sum of the numbers of words transmitted by the other CPUs.
• Use the values in Table5.4 for N1 to N4.
High Performance model QCPU/
Process CPU
Q02CPU
Q02HCPU, Q06HCPU, Q12HCPU,
Q25HCPU
Q02PHCPU, Q06PHCPU, Q12PHCPU,
Q25PHCPU
CHAPTER5 PROCESSING TIME OF QCPU IN MULTIPLE CPU SYSTEM
N4 + (No. of reception word points)
(Example) When No. of CPU is set to 3 and the host CPU is CPU No. 1
The number of received words is the sum of the numbers of
words sent by CPUs No.2 to No.3.
Table5.3 Auto refresh time
N1
63 s
57 s
+ (N3 + (No. of transmission word points)
(Example) When No. of CPU is set to 4 and the host CPU is CPU No. 1
The number of received words is the sum of the numbers of
words sent by CPUs No.2 to No.4.
Table5.4 Auto refresh time
N1
82 s
27 s
N2)) +
N5) (µs)
N2 N3
1.13 s 63 s
1.03 s 57 s
N2) (No. of other CPUs)
N4) (µs)
N2 N3
0.52 s 106 s
0.44 s 27 s
N4 N5
161 s 0.88 s
146 s 0.80 s
N4
0.17 s
0.08 s
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