Data Translation DT9834 Series, User Manual

Page: 90 / 186

Chapter 5
90
Refer to page 55 for information about how to wire analog output signals to the module.
The DACs are deglitched to prevent noise from interfering with the output signal. They power
up to a value of 0 V ±10 mV. Unplugging the module resets the DACs to 0 V.
The DT9834 Series modules can output data from a single DAC or sequentially from one or
more DACs and/or the digital output port. The following subsections describe how to specify
the DACs/port.
Specifying a Single Analog Output Channel
The simplest way to output data from a single DAC is to specify the channel for a single-value
analog output operation using software; refer to
page 92 for more information about
single-value operations.
You can also specify a single DAC using the output channel list, described in the next section.
Specifying Multiple Analog Output Channels and/or the Digital Output Port
You can output data from one or more DACs and/or the digital output port using the output
channel list. This feature is particularly useful when you want to correlate the timing of analog
and digital output events.
Using software, specify the data flow mode as continuous for the D/A subsystem (described
on
page 92 ) and specify the output channels you want to update, where 0 is DAC0, 1 is DAC1,
2 is DAC2, 3 is DAC3, and 4 is the digital output port. You can enter a maximum of 5 entries in
the output channel list and the channels must be in order. Note that you can skip a channel in
the list, however, if you do not want to update it.
For example, if you want to update only DAC3 and the digital output port, specify channels 3
and 4 in the output channel list. If you want to update all the DACs and the digital output
ports, specify channels 0, 1, 2, 3, and 4 in the output channel list. The channels are output in
order from the first entry in the list to the last entry in the list.
The amount of data that you can output for each channel depends on how many channels are
in the output channel list. For example, if only one channel is entered in the output channel
list, you can output up to 128K values; if all five channels are entered in the output channel
list, you an output up to 24K values per channel.
Maximum Rate
The maximum rate at which the module can update the output channels depends on the total
number of channels in the output channel list. Since the maximum throughput for each output
channel is 500 kSamples/s, the module can update two output channels at a rate of
1000 kSamples/s or all five output channels at a rate of 2.5 MSamples/s.