3156B User Manual
Racal Instrument © 2005
Programming Reference 5-27
2 SEQ. The sequenced mode is used for generating a
sequence of memory segments. The definition of the
sequence is stored in a sequence table where
segments can be linked and looped in a user defined
fashion.
3 MOD. The modulation mode is used for generating
modulated waveforms. The modulated carrier signal
is always sine waveform. The carrier can be
modulated using one of the following modulation
modes: FM, AM, FSK, SWEEP and HOP
4 VIDEO - The video stoke is used for generating
special video signals for driving TV's and analog
monitors. In this mode, both channels operate
simultaneously and in conjunction with each other,
similar to XY mode in oscilloscopes. Therefore, any
setting of global operation mode other than both
channels set to video will result in setting conflict
error
5 DIGITAL - The digital output mode cannot be turned
off! Whenever there is a signal at the output
connector, there is signal on the digital output lines
as they are connected in parallel and buffered from
the 12 bits (out of 16) that drive the DAC. If you
specifically select the Digital mode, you also need to
select if you want to operate in free-running or
stimulus run mode.
Default Value: 0
carrierRunMode
ViInt16
This switch defines the run mode for the 3156B. Select
one of CONT, TRIG, GATED and BURST. Setting up the
global run mode is mandatory for correct operation of the
instrument. The 3156B has a lot of capability and
functionality built into it and, at time, incorrect initialization
of its global operating and run modes may cause
numerous setting conflicts. It is therefore recommended
to always use this function as part of the initialization
process. Possible setting conflicts are listed in Chapter 3.
Note that Set Output On command alone will not enable
the 3156B to generate signal at its output connectors.
The Set Output On command activates a relay that
connects the output circuit to the output connector. To
start generating waveforms, the 3156B must be enabled
using either a software enable or hardware enable
commands, or combination of both. Hardware commands
are valid trigger signals that are applied to the
appropriate trigger input
Valid Range: 0-3
0 Continuous - continuous Waveform is generated
following a valid Operate Enable signal or command,
Trigger Delay ON will delay the first output by the
amount set with the trigger delay parameter. Re-
trigger delay has no effect on the continuous
