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TTP-243 Plus/ 243E Plus/
342 Plus Bar Code Printer
5.7 Testing Sensors
A. Checking Ribbon Sensor
Switch the multimeter to the DC gear. Connect the black wire to DC GND, and the red
wire to PIN2 of JP2.
1. When ribbon is detected between TX and RX of the ribbon sensor, the measured
voltage should be 5 Vdc.
2. When ribbon is not detected between TX and RX of the ribbon sensor, the measured
voltage should be 0 Vdc.
The ribbon sensor is normal if the checking complies with the two cases above. Or else,
the ribbon sensor is out of order.
B. Checking DC Motor Encoder Sensor
Switch the multimeter to the DC gear. Connect the black wire to DC GND, and the red
wire to PIN2 of JP6.
1. When gap of the gear box is detected by the DC motor encoder sensor, the
measured voltage should be 5 Vdc.
2. When gap of the gear box is not detected by the DC motor encoder sensor, the
measured voltage should be 0 Vdc.
The DC motor encoder sensor is normal if the checking complies with the two cases
above. Or else, the DC motor encoder sensor is out of order.
C. Checking Gap Sensor
Do gap calibration first by holding the Pause button and activating the printer power at
the same time. If the calibration result is OK, go on and check the gap sensor. Switch
the multimeter to the DC gear. Connect the black wire to DC GND, and the red wire to
PIN2 of JP5. Load label on the printer.
1. When gap (backing paper only) is detected between TX and RX of the gap sensor,
the measured voltage should be 0 Vdc.
2. When gap (backing paper only) is not detected between TX and RX of the gap
sensor, the measured voltage should be 5 Vdc.
The gap sensor is normal if the checking complies with the two cases above. Or else,
the gap sensor is out of order.
