7-10
Host Interface Circuit
TM-U375P has an IEEE 1284 parallel interface for connection to the host computer. The control CPU (I/F circuit board
U2) controls the transmission with the host computer, and the CPU converts the received data to serial data and sends
it to the main circuit board CPU. TTL IC (I/F circuit board U1, U9, and U10) drive or receive I/F signal. For the
transmission with host, the printer supports IEEE 1284 compatibility mode that is normally used for data transmission
from host to printer and IEEE 1284 nibble/byte mode that transmits in the reverse direction.
Refer to the parallel interface circuit board parts layout shown later in this chapter.
Drawer Kick-out Drive Circuit
The DKD_1 and DKD_2 signals from the CPU set the drawer kick-out driver transistors Q7 and Q8 to on; they in turn
output the drawer open signal. The drawer status signal DK_S is input to the gate array, allowing the host to check the
status via the interface.
The +24V drawer power supply is controlled by the three-pin regulator (U1) which cuts off the supply in case of
excessive current.
Figure 7-6. TM-U375P Drawer Kick-out Drive Circuit
CONFIDENTIAL
Summary of Contents for U375 - TM B/W Dot-matrix Printer
Page 2: ...Technical manual TM U375 U375P English 4005791 Copied Date 199 Copied by ...
Page 54: ...2 23 Figure 2 44 Host Interface Circuit and Custor Display Interface Circuit CONFIDENTIAL ...
Page 58: ...2 27 Figure 2 49 Carriage Motor Drive Signal Timing Chart CONFIDENTIAL ...
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