NCR 7156, Руководство по эксплуатации и устранению неисправностей

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Chapter 3: In-Place MICR Adjustment 21
Chapter 3: In-Place MICR Adjustment
Use this adjustment to the MICR amplifier to provide the most
effective interference suppression given the printer environment
during MICR reading. The environment includes any large metal
surfaces under or near the printer and the CRT monitor. The CRT
monitor creates interference through a series of polarized pulses
generated by the deflection coils on the sides of the CRT tube. This
interference affects the noise adjustment process more, and in a
different way, than the interference from the stepping motor.
Setup for In-Place MICR Adjustment
This procedure implements a resident printer adjustment capability
that suppresses interference from the stepping motor to allow for
accurate MICR reading.
The printer should be in the position and orientation that the customer
will be using. If there is a CRT monitor next to the printer, turn it off or
position it as far as possible from the printer (at least 3 inches).
Warning: If the CRT monitor remains on or too close to the printer
during the in-place adjustment, you will not attain the optimum
adjustment. It may be inadequate for the level of suppression
necessary for the stepping motor interference.
1. Record the current DIP switch settings.
2. Set the DIP switches as shown in the following table.
Switch 1 2 3 4 5 6 7 8
ON OFF OFF OFF OFF OFF ON Don’t
Care
3. Check that there is sufficient receipt paper loaded for testing and
that both the top cover and the front cover are tightly closed.