| Directions: |
|
Enter a master speed command in percent, as
whole numbers. Maximum speed is 100%.
Click "Master Line Speed" to
enter the command.
Enter the Follower Speed Ratio in percent (use integers only)
Click "Follower Speed Ratio" to enter the command
The follower in this example can go 1% of the Master's speed, to 200%
of the Master's speed. |
| System
Basics |
| This
system uses a typical "Master Reference Control". The actual control
can be a multi-channel analog option card with signal isolation for each
channel. It could be a PLC or signal isolator card as well. These options are
generally used in multi-motor systems where one line speed command will be
output to many drives. A master line speed command is given to one drive, and
the others become "follower" drives. In this system, the drives
operate "open loop" with no speed feedback for error correction. |
| Benefits
of this system |
|
|
| Drawbacks
and Pitfalls of this system |
-
When
coordinated control is NOT desired, switching to independent control can
be complex.
-
Scaling
of each drive speed can require running product for a considerable time.
-
PLC
based master reference controls can have many parameters such as bias,
gain and offset.
-
Troubleshooting
each channel of speed reference can be difficult.
|
| Basic
Bill of Materials for the system shown (excluding power transmission, etc.) |
-
Master
reference control option device (analog card, PLC, etc)
-
Power
supply, fused
-
Electrical
enclosure to house option device and peripheral devices
-
2
vsd's
-
2
motors
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