Specifications

Chapter 2 Functions
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2-2-2 Command transmitting system
Two systems are provided for transmitting command pulses: [open collector] and [line driver].
◆ Open collector system
This system employs a transistor whose emitter is
common and whose collector is open. Since the
output signal is voltage type, this system is
unsuitable for long distance transmission due to line
voltage drop.
◆ Line driver system
The line driver system conforms to (EIA) RS-422
standard providing line drivers for transmitting
signal pulses. Since the output signal is current type,
this system is suitable for long distance
transmissions without attenuation of signals.
Furthermore, the line driver system transmits data
faster than the open collector system.
2-2-3 Outputting encoder signals
Two kinds of encoder are selectable for the FHA-C
series actuator: incremental or absolute. The
incremental encoder feeds back two pulse-trains
into the HA-655 driver as shown in the figure to the
right. The pulse trains are called [phase-A] and
[phase-B]. For the encoder resolution, refer to
actuator’s technical manual.
On the other hand, the absolute encoder feeds back
a combination of absolute signals and two
pulse-train signals.
In addition to the 2-phase pulse trains, both
encoders output a [phase-Z] pulse signal once per
motor rotation for use as an origin. The pulse signal
is sometimes called [phase-C] or [index].
The HA-655 driver outputs encoder signals using a
line driver system. The signals can be received by a
line receiver: AM26LS32 (EIA-422A) or equivalent.
Phase-Z signal is also available (open collector
output {CN-42 pin}).
The phase-Z signal is asynchronous.
Three encoder signals mentioned above are
available for a host.
● Relating I/O pins
Output pins: CN2-42 to 49
Input
Transmission
line
Line driver
Use twist
pair cable.
Output
Phase-A
Phase-B
Phase-Z
Forward
Phase-A
Phase-B
Phase-Z
Reverse
Emitter
Input
Transmission
line
Collector
Use twist
pair cable.
Output