Table of Contents
Advertisement
REV.-A
2.4.1.5 TE Holder Motor Control
Figure 2-34 shows the block diagram of the TE holder motor control circuit. In the main circuit, motor
phase switching is not directly carried out by the CPU, but is instead carried out by the DCU (2A)
according to the pulses sent from the MMU (8B). The DCU is enabled by the MMI03 signal LOW sent
from the MMU. After the DCU first sets addresses AO-A3, it sets the excitation method (2-2 phase or
1-2 phase) and the revolution direction (CW or CCW) according to the SCK/RCK port settings and, if
the pulse (TETM signal) is input to the TM2 terminal by the MMU, automatic switching of the stepping
motor is carried out. The operation wave forms for the TM2 and TEA signals are shown in Figure 2-35.
Furthermore, HIGH/LOW is set to port PO according to similar address settings and SCK/RCK port
settings. Accordingly, switchover of the common voltage is carried out (TEENB signal). The firmware
drives the TE holder motor with the two different speeds shown below.
(1) Synchronous mode
This drive is for when the platen (paper feed motor) turning speed and the TE holder plate speed
are approximately equal, such as when the print characters are near the top edge of the paper, micro
feed, and line feed. While the paper feed motor is driven in the 4-phase mode, the TE holder is driven
in the 1-phase mode.
(2) Independent mode
When re-supplying paper, this drive is for when the TE holder plate only operates independently,
such as when it moves to the paper guide auxiliary plate position or when it returns to its home
position. This operation is for normal and independent revolution operations, and from the
revolution operation until it stops, the following operations are realized:
1. Acceleration control
2. Constant-speed control
3. Main control
In each mode, the phase switching time settings (TETM pulse switchover time) differ. (See Figure 2-36)
AD-A3
AD
WR
~~
L
SCK
ADDRESS DEC ODER
- -
MODE SELECTOR
RCK
CPU
MMU
~
-
-
- -
-
- - - - - - -
- -
(IQC)
f--
(8B)
TETM
- -
PI
TM2
AUTO
. .
PHASE
)
IT
SWITHING
y
MMIOt03J
DCU
-
(2AJ
PO
~
TEA,TEA,
TEB,TEB
TEENB
Figure 2-34. Top Edge Holding Control Circuit Block Diagram
2-34
Advertisement
Table of Contents
