Omron CS1W-MCH71 Operation Manual page 67

Performance
Calculation Method for
Communications Cycle
22
Note for P00003 [Unit Scan time]
When P00003 [Unit Scan time] is greater than the result of the formula (1), the
formula (2) below is to be used.
Unit Cycle [ µ s] = P00003 × 1000 ---(2)
Determining Unit Cycle
The Unit Cycle can be determined by rounding up the Unit Cycle [ µ s] that was
found by the formula (1) or (2) to 1 ms, 2 ms, 3 ms, 4 ms, 6 ms, or 8 ms.
If the unit cycle time exceeds 8 ms, 8 ms is set.
Basic formula for calculating Communications Cycle is shown below:
Communications Cycle [ µ s] = ((No. of allocated nodes + No. of Retries) ×
102.7 + 19.2) × 1.1 ---(3)
• No. of Allocated Node: No. of MECHATROLINK-II slaves (only physical
• No. of Retries: No. of retries specified in [P00009: MECHATROLINK No.
If the Communications cycle was less than 1ms, the formula (4) below is to be
used.
Communications cycle [ µ s] = 1000 ---(4)
Determining Communications Cycle
The Communications Cycle can be determined by rounding up the Communi-
cations Cycle [ µ s] that was found by the formula (3) or (4) to 1 ms, 2 ms, 3 ms,
or 4 ms.
If the communications cycle time exceeds 4 ms, 4 ms is set.
Note The formula used in this section applies when P00004 bit 09 is 1 for a CJ1W-
MCH71 or CS1W-MCH71 Motion Control Unit with unit version 3.0 or later.
If the unit version is 2.0 or earlier, or the unit is version 3.0 or later but P00004
bit 09 is 0, the following formula applies.
Unit cycle [ µ s] = (115.0 × Number of axes) + (165.0 × Number of motion tasks
× Number of parallel branches) + (0.3 × Number of general allocated words) +
350.0
Communications cycle [ µ s] = ((No. of allocated nodes + No. of Retries) ×
133.3 + 26.2) × 1.1
axes) allocated in [P1AA01: Physical Axis Setting]
of retrial nodes setting] (= 0-7).
Section 1-7