HP 53131A, Operating Manual

Page: 119 / 196

Chapter 2 Operating Your Universal Counter
Using the LIMITS Menu Keys
Operating Guide 2-43
2
Limits Testing Example 5—Sending the Limit-Detect Output
to the RS-232 Serial Port
NOTE If you cycle power, you will lose everything except saved measurement
setups and special parameters saved to non-volatile memory; therefore,
make sure you use the Save and Recall functions of the Counter to retain
the measurement setup prior to powering down to set up the the
Limit-Detect Output line (pin 4) of the RS-232 serial connector. Refer to
the appropriate section in this chapter for details on how to use Save and
Recall.
1 To use the Limit-detect output from the serial port, perform the following
steps:
a. Save your measurement setup that includes your Limit Testing
choices, by simply pressing the Save & Print key until SAVE: 1 is
displayed, then Enter key to save to register 1.
b. Turn off the Counter.
c. Press and hold Recall (Utility) key, then press POWER key.
d. Press Recall (Utility) key until DTR: is displayed.
e. Press any one of the arrow keys until DTR: LIMIT is displayed.
2 Press Run key.
3 Press Recall (Utility) key until RECALL 1 is displayed, then wait a few
seconds to recall the measurement setup saved in register 1.
Since your measurement setup included your settings for upper and lower
limits, and
LIM TEST: was set to ON , the Counter is now set for limit
testing with the Limit-detect output.
If a measurement drifts out of the user-entered limits, the Limit
annunciator in the display will light. Also, pin 4 on the RS-232 connector
will change state (to a low-voltage RS-232 level) to flag each time a
measurement drifts out of the limits. (RS-232 voltage levels swing
from ±12V.)