Technical Guide: Channel Multiplexing
One of the more unique features of the Quantum Composer pulse generators is the ability to combine the timing of any or all channels together and output them out of any of the output
BNCs. The multiplexing function (MUX) can be set through remote communications via a computer or from the front panel of most units. The MUX feature is available on all of the
standard Quantum Composer voltage output pulse generators from the price minded Sapphire series (9200 model) to the feature rich 9520 series. The feature operates the same in all of
the models and the setup for the MUX feature is identical across the different product lines. The MUX feature combines the timing parameters (width and delay settings) of multiple
channels together on one output to create complex pulse train outputs. The output channel selected can also add its timing to the final output train (Fig. 1). The third pulse of the
combined pulse output (Channel 4 in Fig. 1) is generated by that specific channel’s settings.
The output amplitude of the combined pulse train will be determined by the output mode setting on the actual output channel. The MUX feature does not combine the actual output voltage
signal together. In other words, combining a standard TTL (5V) output channel with an adjustable voltage output (10V) will not generate an output that has both 5V and 10V outputs
Each output channel has its own MUX setting located in the channel menu structure. The channel menu structures are similar for most of the pulse generator models and a video of the
9520 channel menu structure can be found on our website (http://www.quantumcomposers.com/support/videos). See figure 3 for an example of the MUX menu on a 9500+ series pulse
The MUX menu show two lines on the display: one indicating the channels of the unit and one indicating what channel timers are being output on that channel. The number under the
channel indicator can either be a 1 or a 0. 1 indicates that the timing is active for that output and a 0 means that it is not. Figure 3 shows the MUX menu for Channel A of a 8
channel 9518+ and indicates that only the timing parameters of channel A are being used for that output.
Figure 4 shows channels A, C, F, and H all multiplexed together on the Channel A output. The channel timing for the output being used (in Fig. 3 and 4 Channel A) does not need to be
output on that particular channel. In that case the output can be just a composite of the other channel outputs. The output amplitude will still be determined by the output channel
but the timing components (width and delay) will not be included. The channel multiplexing feature (MUX) is just one of many unique and powerful features that the Quantum Composers
pulse generators have to offer.