Test Products International 460 - Manual (Page 64)

Note that in terms of shape, the sine and sawtooth waveforms are hardly effected. Only the
squaretooth waveform shows excessive shape change effect and, for this type of attenuation,
mostly effecting the leading edge.
Refer to the procedure outlined in chapter 4 which uses a square wave to adjust the 10:1 probe
for proper compensation
RS-232 link will not capture waveforms.
This problem is usually associated with the computer not looking at the right port. The display
software is local to the PC, but the data is coming across the 440 computer interconnect. Also,
the software driver will not allow a new port to be addressed without the connection being effec-
tively shut down.
On the RS-232 display, note the Comm Port and Baud Rates being addressed. Defaults are usu-
ally 9600 Baud and Comm Port 2. Click the Stop button. Click Comm Port 1, then click Start.
This usually will fix the problem. If not, go through all the Comm Port options, being sure to
cycle the Stop/Start buttons between each choice. If you still do not see the trace displayed,
repeat the same process with a different Baud Rate.
A less common problem, but one you should check, is that the chosen trace/graph color is differ-
ent from the background color. Select Color Set Up, and check or change the three color option
boxes. Once you click a color box you will be presented with a full color palette to chose from.
Once you have selected choices from the above options, the settings will remain until they are re-
selected and changed.
RS-232 Waveform updates too slowly
This problem could be Baud Rate or sample time. If the displayed Baud Rate is slower than
9600, try the faster rate. Select Stop, then 9600, then Start.
The Sample Rate (S/Rate), is selectable from 1 to 9999 seconds. Click the S/Rate box, then
enter the required sample rate. The fastest available sample rate is 1 Sec.
Trouble effectively archiving RS-232 waveforms
The following problems could arise when attempting to archive waveforms captured using the
RS-232C / PC interface
The RS 232 screen was not issued a file name / identifier to store the waveform
under. Use the mouse to click on the save button and enter an identifier label
in the Save File Name As dialog box. Then click Ok.
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460 User s Guide Troubleshooting