4．7
Signal Output Circuit
(1) Output Circuit
As shown in the diagram at left, an open collector transistor is used for the
output circuits, which requires an external power supply.
This connection is necessary only if the speed monitor and alarm function
are used. This power supply should be DC26.4V or less. Also connect a
limiting resistor suitable for the power supply voltage to keep the current
from exceeding 10mA. Output circuit is insulated from dangerous voltages
by the reinforced photo couplers.
(2) Example of Output Signal Connections
■
This connection is used for ALARM and SPEED output.
■
Speed Signals
It is output at a rate of 12 pulse per motor rotation.
Motor rotation rate can be determined with the following formula;
The pulse length of the signal that turns speed output on (low) is 0.9msec, regardless of motor speed.
■
Alarm Output
This signal is output when one of the driver's protection functions is activated.
While the signal is output, terminals between ALARM OUT and GND is a electrified.
See page 16 for the descriptions of these protection functions.
15
Reinforce photo coupler
SPEED OUT
ALARM OUT
GND
2.7k
Ωmin.
Photocoupler
DC24V
Controller
GND
Driver
Output
External connection
0.9msec
Speed signal output waveform
T
Driver
Motor Speed [r/min]=
×60
=Speed output frequency
Speed output frequency [Hz]
12
1
T
4．8
Noise Control
When excessive external noise works its way into the driver, malfunctions can result. To prevent problems caused by noise,
take the following countermeasures.
■
Power Supply Lines
・Separate the power line of the noise source from the driver's power line.
・The driver must be earthed with the earth wire of the protective earth terminal.
■
Signal Lines (
Ⅰ
/O)
・Keep the signal line as short as possible (2 meters or less).
・When setting speed by means of the external speed potentiometer or a DC voltage, use the signal line provided with the unit.
・Separate power lines at least 30 cm from any cable running a large current.
■
Feedback signals between the motor and driver
Place motor cable at least 30 cm away from any cable running a large current.
