Omron CS1W-MC221 - 02-2008 Operation Manual page 581

Performance
Unit Startup Time
When the MC Unit is turned ON or reset, it performs initialization processing and then turns ON the Manual
Mode Flag. The MC Unit can receive commands from the CPU Unit only after the Manual Mode Flag has
turned ON. Approximately 600 ms is required for the Manual Mode Flag to be turned ON.
Affects on CPU Unit Cycle Time
The cycle time of the CPU Unit will be increased by the following time for each MC Unit mounted in the PLC.
The time will be longer when the motors are moving than when the servos are unlocked.
Model
Time increase per Unit
The cycle time will also be increased if the IOWR or IORD instructions are used to read/write position data or
parameters in the MC Unit. The following tables shows the increase in the cycle time when position data for 1
to 4 positions is read or written.
Instruction
IOWR (per instruction)
IORD (per instruction)
Data Transfer and Saving Times
Large volumes of data can be written to or read from the command area using the IOWR instructions. Refer to
SECTION 4 Data Transfer and Storage for details on using the command area to transfer data.
The data read/write times are listed in the following tables.
Up to 20 words can be transferred per CPU Unit cycle. Longer CPU Unit cycle times will thus increase the data
transfer time.
Conditions: All axes are servo-locked and stopped.
The CPU Unit cycle time is 2 ms.
Data Read Times (Command: 17D7 Hex)
Number of words read
3 words (1 position)
30 words (10 positions)
300 words (100 positions)
1,500 words (500 positions)
3,000 words (1,000 positions)
Data Write Times (Command: 17D6 Hex)
Number of words read
3 words (1 position)
30 words (10 positions)
300 words (100 positions)
554
Power turned ON or Unit restarted
Manual Mode Flag
CS1W-MC221
0.2 to 0.8 ms
CS1W-MC221
0.4 to 0.7 ms
0.4 to 0.8 ms
CS1W-MC221
37 ms
37 ms
60 ms
205 ms
390 ms
CS1W-MC221
37 ms
37 ms
60 ms
Unit startup time
CS1W-MC421
0.25 to 0.85 ms
CS1W-MC421
0.4 to 0.7 ms
0.4 to 0.8 ms
CS1W-MC421
37 ms
45 ms
77 ms
245 ms
470 ms
CS1W-MC421
37 ms
45 ms
77 ms
Appendix A