3156B User Manual
WaveCAD 4-26
Racal Instrument © 2005
Note
Normal color of the digital reading is dark blue. If you
modify the reading, the color changes to a lighter shade of
blue, indicating that the 3156B has not been updated yet
with the new parameter. Pressing Execute will update the
instrument and will restore the color of the digital readout
to dark blue, indicating that the displayed value is the
same as the generator setting.
Also note that the digital readout has an autodetect
mechanism for the high and low limits. You cannot exceed
the limits if you are using the dial but only if you use the
keypad. In case you do, the program will not let you
download an illegal parameter and you’ll be requested to
correct your setting.
The FSK Data table, as shown in Figure 4-11, programs a sequence
of bits that are associated to an index number. The 3156B steps
through the programmed index number and shifts or returns the carrier
frequency according to the “0” and “1” list. When the index line is “0”,
the instrument generates sine waveforms with frequency set by the
carrier frequency parameter. When the index line is “1”, the generator
modifies the sine waveform frequency to the shifted frequency setting.
