Effects Of Master Units On Cpu Unit Cycle Time - Omron CS1W-CRM21 Operation Manual

Remote I/O Communications Performance
Note
Communications
mode
Communications
mode 3
Communications
mode 8
5-3-2

Effects of Master Units on CPU Unit Cycle Time

CS Series
Communications Communica-
mode tions mode 0
CPU Unit model
CS1G CPU Unit 0.244 ms
CS1G-H CPU Unit 0.189 ms
CS1H CPU Unit 0.200 ms
CS1H-H CPU Unit 0.156 ms
148
• TCrmInMin: Minimum input processing time at Master Unit
Communica- Communica-
tions mode 3 tions mode 8
0.093 ms 0.46 ms + P
(See note.)
Communications Mode 8
P = (Number of Word Input Slave Units × 0.25 µ s) + [{(Number of Bit Input
Slave Units × 7) ÷ 8} × 0.375 µ s] + [(Number of Word Output Slave Units or
Word Input Slave Units, whichever is greater) + (Number of Bit Output Slave
Units and Bit Input Slave Units, whichever is greater) × 0.5 µ s]
P Calculation Example
Conditions
Baud rate Word outputs
--- 63 nodes
P= (64 × 0.25 µs) + (16 × 0.375 µs) + ((64 + 128) × 0.5 µs) = 0.118 ms
■ Reference Example
The following table shows the calculation results for the maximum I/O
response time for a Bit Slave Unit with the minimum number of nodes and a
CPU Unit cycle time of 1 ms.
Number of nodes con-
nected
32 word nodes (16 input, 16
output)
128 bit nodes (64 bit input,
64 bit output)
128 word nodes (64 input,
64 output)
256 bit nodes (128 bit input,
128 bit output)
CPU Unit cycle time is affected by the number of Master Units mounted and
the communications mode that is used (e.g., the number of words allocated
for Slave Units in the I/O Memory Area when communications mode 8 is
used).
The following tables show the additional time per Master Unit on CPU Unit
cycle time for each communications mode.
Communica-
tions mode 1
0.278 ms
0.211 ms
0.233 ms
0.167 ms
Word inputs
64 nodes
Word Slave Unit max. I/O response time (ms)
4.0 Mbit/s 3.0 Mbit/s
4.9 5.0
5.7 5.9
Communica- Communica-
tions mode 2 tions mode 3
0.344 ms 0.367 ms
0.233 ms 0.289 ms
0.300 ms 0.311 ms
0.200 ms 0.244 ms
Section 5-3
Bit outputs Bit inputs
128 nodes 127 nodes
1.5 Mbit/s 93.75 kbit/s
5.5 16.2
6.6 26.3
Communications mode 8
0.180 + (0.0024 x number
of words allocated) ms
0.135 + (0.0014 x number
of words allocated) ms
0.150 + (0.0022 x number
of words allocated) ms
0.105 + (0.0012 x number
of words allocated) ms