Sample Clock; 10 Mhz Ref; Sequence Advance - Racal Instruments 3155 User Manual

Sample Clock

10 MHz Ref The 10 MHz Ref group is a duplicate of the same group in the Main

Sequence Advance

3-14 ArbConnection
The Sample Clock group consists of one parameter that controls the
sample clock frequency. Note that the sample clock rate is pro-
grammed in units of S/s (samples per second) and will affect the
Model 3155 only when it is programmed to output arbitrary or se-
quenced waveforms.
To access the required parameter, click on the button until the LED
next to the required parameter turns on. The value associated with
the lit LED is displayed on the digital display. You can use the dial,
keyboard, or the [↑] [↓} keys to adjust the readout to the required
setting. After modifying the reading, press Execute to update the
3155 with the new reading.
Panel. The 10 MHz Ref group provides selection between internal
(CLK10), external, or TCXO references. Click on the Internal button
to select the Internal CLK10 reference, the External button to activate
the external reference input, or the TCXO button to select the better
accuracy and stability option (if installed).
By selecting an external reference you are disabling the
internal reference circuit. If you do not have a 10 MHz
reference connected to the instrument, the output will
generate erroneous frequencies.
The Sequence Advance group provides control over advance modes
for the sequence generator. Advance options are: Auto, Stepped,
Single and Mixed. Refer to the 3155 programming section to find out
more about when and how to use these advance modes. You should
be careful while selecting modes because it is possible to cause a
settings conflict, for example, if you select the Single option and for-
got to change to the triggered mode.
The Sequence advance group lets you also select the source for
triggering the advance of the sequence steps. Descriptions of the
various advance sources are given below.
External – selects the TRIG IN input as the advance source. Note
that this option affects the generator only when it is placed in an op-
erational mode which requires trigger stimuli.
WARNING
User Manual 3155