18
OPERATING INFORMATION
Capacitive loads may be driven as well, provided a 50 ohm termination is used in parallel with the
capacitance. In most cases best results are obtained when the capacitance is located at a T (with
minimul stub length) close to the 50 ohm terminator (which should be placed at the most distant end of
the cable system). A capacitance will act as a momentary short, and will generate aberrations that
depend on the size of the capacitance. A capacitance too large will trip the short circuit protection. Rise
and fall times will be longer with a capacitive load.
TROUBLESHOOTING
Follow the procedure in the Troubleshooting section of the 6040 manual. Make sure that the module is
seated correctly in the mainframe. If the module's memory has been corrupted, a cold boot will put the
module's default settings into effect (as described in the Cold Boot section in the 6040 manual). Table 2-
3 gives the default settings for the 202H module.
Table 2-3. 202H Module Default Settings
The Quick Test procedure for the mainframe may be applied to the 202H by selecting the Pulse Mode
and following the test sequence using the module's PULSE OUT connector in place of the mainfame's
PULSE OUT.
If the output drops in level or the front panel LEDs blink, check that a 50 ohm load is being used (see
Load Requirements). Also check that duty factor and repetition rate maximums are
not being exceeded (see the Timing Requirements and Protection Features sections). For problems
relating to output pulse aberrations, refer to the section on Cables and Load Placement.
MODE:
Pulse
TRIG:
Single Cycle (with other values set as follows)
Internal Trigger Rate = 1kHz
External Trigger Threshold = 0.00 V
Trigger Slope +
TIMING:
Delay = 0 ns
Width = 1.00
s
Single = Pulse
LEVEL:
Peak = 30 V
GPIB/RS-232:
GPIB Address = 6
Baud Rate = 1200
Full Duplex
Remote Enable
