Oriental motor BLH Series - Multi-Motor Control

36
Operation
7.9 Multi-motor control
Operating two or more motors at the same speed can be performed using any of the external potentiometer, external
DC voltage, or PWM signal.
Using an external potentiometer
Use common lines for the power supply and speed setting, and set the speed using VRx as shown in the gure below.
•
Obtain the resistance value for the external speed potentiometer as follows.
Resistance VRx when the number of drivers is n units: VRx (k
Ω
) = 20 k
Ω
/n, permissible dissipation (W) = n/20
Example: If two drivers are connected, 10 k
Ω
and 1/10 W are obtained.
•
For I/O signals other than the speed setting, connect for each driver.
•
If multiple motors are used with speed dierences among them, adjust as follows.
The rst driver: Connect a resistor of 1.5 k
Ω
, 1/20 W to the terminal M on the driver.
The second and subsequent drivers: Connect a variable resistor (VRn) of 5 k
Ω
, 1/20 W to the terminal M on the driver.
•
Keep the number of drivers to 10 units or less in multi-motor control using an external potentiometer.
3
2
VRx
1
Speed setting line
1.5 kΩ, 1/20 W
VRn
5 kΩ, 1/20 W
VH
VM
VL
Driver
Driver
Power line
CN2
CN1
+24 V
GND
CN2
CN1
+24 V
GND
VH
VM
VL
Using external DC voltage
•
Use a DC power supply whose current capacity is at least the value calculated by the formula below.
Current capacity (mA) when the number of drivers is n units = 1mA × n
Example: If two drivers are connected, the current capacity should be at least 2 mA.
•
For I/O signals other than the speed setting, connect for each driver.
•
If multiple motors are used with speed dierences among them, adjust as follows.
The rst driver: Connect a resistor of 1.5 k
Ω
, 1/20 W to the terminal M on the driver.
The second and subsequent drivers: Connect a variable resistor (VRn) of 5 k
Ω
, 1/20 W to the terminal M on the driver.
Speed setting line
DC power supply
0 to 5 VDC
+
1.5 kΩ, 1/20 W
VRn
5 kΩ, 1/20 W
Power line
Driver
CN2
CN1
+24 V
GND
Driver
CN2
CN1
+24 V
GND
VH
VM
VL
VH
VM
VL
–

How to adjust the speed dierence
To adjust the speed dierence among the rst motor and the second and subsequent motors, change the "External
analog operation speed command oset" parameter. Refer to p.46 for the parameter.
When the speed dierence is adjusted by changing the parameter, no resistor for adjusting the speed dierence is
required.
The speed dierence can be adjusted by changing the "setting voltage - rotation speed characteristics" shown in the gure.
0
Rotation speed
Setting voltage
Positive
side
Range of External
analog operation
speed command oset
(–1500 to +1500 r/min)
Negative
side
[Example]
•
When the speed of the second motor is slower than
that of the rst motor, set a value for the positive side
(0 to +1500r/min) in the "External analog operation
speed command oset" parameter of the second driver.