REV.-A
2 . 4 . 5 C a r r i a g e M o t o r
This section describes the sensor circuit, an outline of the firmware, and the drive circuit, which are
used to control the carriage motor. The specifications of the carriage motor are as follows:
Angle per step:
Number of steps per revolution:
Number of phases:
Excitation system and drive frequency:
Drive voltage:
Resistance per coil:
2.4.5.1 Home Position Sensor
7.5°
48 steps
Four
drive, 2-2 phase excitation system (900
drive,
phase excitation system (450
+24 VDC
41.5 ohms
The home position sensor detects the reference position of
the
carriage. The sensor is located at the
home position which is to the left of the first column. Figure 2-18 shows the home position sensor circuit.
+ 5
R 20
CN7
5.6K
I
- - HOME
r
-
I
Home Position
I
Sensor
1
I
1
2
Fig. 2-18. Home
R32
(3B)
Position Sensor Circuit
When the carriage is at the home position, the reed switch is closed, and a LOW signal is input to the
HOME terminal of the
The CPU reads
port XX H of the
to determine when
the carriage is at the home position.
2-23