Specifications

REV.-B
2.3.4 MOTOR, CR Drive Circuit
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Figure 2-22 shows the MOTOR, CR drive circuit. An open-loop, constant-current drive arrangement is
used for running the MOTOR, CR. The motor is driven by 2.2 phase excitation and l-2 phase excitation.
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2-2 phase excitation corresponds to two l-2 phase excitation steps. Thus, for each single step phase
change of a 2-2 phase excitation motor, the carriage moves l/l 20 inch. For each single step phase
change of a l-2 phase excitation motor, the carriage moves l/240 inch.
The MOTOR, CR drive circuit of the STK-6022B detects the amount of current flowing in the MOTOR,
CR coil and regulates this current. The current flowing through the coil varies, depending on the speed
of the MOTOR, CR. The amount of current is set by the CPU via the E05A50 I/O port. Signals are sent
to SELRl to SELR4 on the STK-6022B. The STK-6022B sets the coil current to correspond to the
MOTOR, CR speed.
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Ports P60 to P63 on the CPU are used exclusively as control ports for the stepping motor.
CPU (1C)
STK-6022B (2A)
P60 ~ GRAIN CRA
P61 ~ CRBIN CRB
P62 ~ CRCIN
CRC
P63 ~ CRDIN
CRD
PO SELR 1
Data
Bus
Pl SELR2
P2 SELR3
CP
P5 SELR4
E05A50(4D)
f Coil Current
MOTOR, CR
20
t
Coil Current
Figure 2-22. MOTOR, CR Drive Circuit
Table 2-6. MOTOR, CR Drive Modes
Drive Mode
3.214 X speed
3 X speed
2 X speed
1.5 X speed
413 X speed
1 X speed
2/3 X speed
1 l/2 X speed
Excitation Type
2-2 phase
2-2 phase
2-2 phase
1-2 phase
1-2 phase
l-2 phase
l-2 phase
1-2 phase
Drive Frequency Type
2700 pps
2520 pps
1680 pps
2520 pps
2240 pps
1680 pps
1120 pps
840 pps
Standard Print Character
High Speed Draft
Draft
LO
2-17