Citizen CL-E700 series Technical Manual page 48

Chapter 2 Operating Principles
2-2.
Operation of Control Parts
Forcible stop of the "SA Ribbon Motor F" at an abnormally high temperature:
If the temperature of the "SA Ribbon Motor F" reaches 85  C (185  F), the "SA Ribbon Motor F"
stops.
In addition, an abnormally high temperature is monitored by the abnormally high temperature
detection circuit. (Refer to
temperature (100  C (212  F)) is detected with this circuit, the FPGA controls the circuits as
follows.
• Changes the level at pin N3 (VMT ON) from "High" to "Low" so that +24V DC (VMT) to the
motor driver (U601) stops.
• Stops the output from the motor driver (U601).
From the temperature error detection circuits, the following error signals nTMPERR
(abnormally high temperature errors) are output to the NAND gate (U11). If any of the
following abnormally high temperature errors occurs, the error signal nTMPERR changes
from "High" level to "Low" level. Thus, pin 2 (ENABLE) of the motor driver (U601) goes to
"High" level to stop its outputs.
• An abnormally high temperature error from the head temperature sensor
• An abnormally high temperature error from the PF motor temperature sensor
• An abnormally high temperature error from the ribbon motor temperature sensor
• An abnormally high temperature error from the cutter temperature sensor (option)
Further, the output from pin 5 of monostable multivibrator (U6B) is used as another
condition to forcibly stop the "SA Ribbon Motor F". If an edge input sent from the CPU
(U1A) to the U6B stops for some reason, pin 5 of U6B goes to "Low" level and the output of
U11 goes to "High" level. As a result, pin 2 (ENABLE) of the motor driver (U601) goes to
"High" level to stop its outputs for safety. This forcible function prevents the "SA Ribbon
Motor F" from being damaged even if an abnormal condition happens.
CL-E700 series
"2-2-4(5) Ribbon motor temperature
2-34
sensor".) If the abnormally high