Tektronix 1503C, User Manual, Page: 25 / 128

Operating Instructions
1503C MTDR User Manual
1–9
can give an indication of the effectiveness of the LCD heater in a cold
environment.
iii. LCD Drive Test Diagnostic generates a moving vertical bar pattern
across the LCD.
iv. Contrast Adjust allows you to adjust the contrast of the LCD. It
generates an alternating four-pixel pattern. The nominal contrast is set
internally. When in Contrast Adjust mode, VERT SCALE is used as the
contrast adjustment control. This value ranges from 0 to 255 units and
is used by the processor to evaluate and correct circuit variations caused
by temperature changes in the environment.
d. Chart Diagnostics Menu offers various tests for the optional chart
recorder.
i. LCD Chart allows adjusting the number of dots per segment and the
number of prints (strikes) per segment.
ii. Head Alignment Chart generates a pattern to allow mechanical
alignment of the optional chart recorder.
6. View Stored Waveform Settings displays the instrument settings for the stored
waveform.
7. Option Port Menu contains three items. Two items allow configuration of the
option port for communicating with devices other than the optional chart
recorder and one item test the option port.
a. Option Port Diagnostic creates a repeating pattern of signals at the option
port to allow service technicians to verify that all signals are present and
working correctly.
b. Set Option Port Timing allows adjustment of the data rate used to
communicate with external devices. The timing rate between bytes can be
set from about 0.05 to 12.8 milliseconds.
c. Option Port Debugging Is Off/On. Off is quiet, On is verbose. This
chooses how detailed the error message reporting will be when communi-
cating with an external device.
It is possible to connect the instrument to a computer through a parallel interface
with a unique software driver. Because different computers vary widely in
processing speed, the instrument must be able to adapt to differing data rates
while communicating with those computers. With user-developed software
drivers, the ability to obtain detailed error messages during the development can
be very useful. For more information, contact your Tektronix Customer Service
representatives. They have information describing the option port hardware and
software protocol and custom development methods available.