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3.3 Multi-CPU Functions
Differences between Sub CPU Synchronization and Slave CPU Synchronization
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3.3
Multi-CPU Functions
The multi-CPU functions allow you to use more than one CPU Unit to control one system.
When you use more than one CPU Unit (i.e., when you use a multi-CPU function), you can divide the
application programming of the Machine Controller. This distributes the application load among the CPU
Units and increases the memory capacity.
There are the following two multi-CPU functions. Determine which function to use based on the number
of CPU Units in the system, the distance between the Racks, etc.
• Sub CPU synchronization
• Slave CPU synchronization
Here, we describe the differences between Sub CPU synchronization and slave CPU synchronization and
provide details on Sub CPU synchronization.
Refer to the following manual for details on slave CPU synchronization.
MP3000 Series Motion Control User’s Manual
(Manual No.: SIEP C880725 11)
Differences between Sub CPU Synchronization and Slave
CPU Synchronization
The following tables gives the differences between Sub CPU synchronization and slave CPU synchroniza-
tion.
You can use Sub CPU synchronization and slave CPU synchronization at the same time.
Information
Item
Sub CPU Synchronization
Slave CPU Synchronization
Connection Method
Connected through MP3000 bus
Connected with MECHATROLINK-III.
Maximum Number of
CPU Units
5 (Main CPU Unit
×
1 and Sub CPU
Units
×
4)
39 (Master CPU Unit
×
1 and Slave CPU
Units
×
38)
Transmission Distance
Maximum distance between stations: 6
m
Maximum distance between stations: 100 m
Data Update Period
between CPU Units
125
μ
s, 250
μ
s, ..., 32 ms
250
μ
s, ..., 32 ms
Refer to the following manual for details.
MP3000 Series Motion Control User’s Man-
ua
l (Manual No.: SIEP C880725 11)
Communications
Scans
Both the high-speed scan and low-speed
scan can be used at the same time.
High-speed scan only
Size of Shared Regis-
ters
For both high-speed and low-speed scans
• Inputs: 2,048 words max.
• Outputs: 2,048 words max.
• Inputs: 32 words max. (Two of those words
are used by the system.)
• Outputs: 32 words max. (Two of those
words are used by the system.)
Starting and Stopping
CPU Units
The Main CPU Unit and Sub CPU Units
are linked.
The Main CPU Unit and Sub CPU Units are
not linked.
WDT Errors
Turning Power ON/
OFF
Motion Control Func-
tionality
Both the Main CPU Unit and Sub CPU
Units can be used as motion control mas-
ters.
The Master CPU Unit can be used as a motion
control master.
A Slave CPU Unit cannot be used as a motion
control master.