Measurement Computing Data Translation DT3034, User Manual

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Chapter 6
72
Specifying One or More Channels
DT3034 boards can read data from one or more analog input channels using an analog input
channel list. You can group the channels in the list sequentially (either starting with 0 or with
any other analog input channel), or randomly. You can also specify a single channel or the
same channel more than once in the list.
Using software, specify the channels in the order you want to sample them. The analog input
channel list corresponds to the channel List FIFO on the board. You can enter up to 1,024
entries. The channels are read in order (using continuously- paced scan mode or triggered
scan mode) from the first entry to the last entry in the channel list. The board can read the
channels in the channel list up to 256 times per trigger (for a total of 262,144 samples per
trigger) using triggered scan mode. Refer to
page 76 for more information on the supported
conversion modes.
Note: If you select an analog input channel as the analog threshold trigger source, the
channel used for this trigger source must be the first channel specified in the analog input
channel list; refer to
page 80 for more information on this trigger source.
If you wish, you can also use software to inhibit data collection from channels in the channel
list. This feature is useful if you want to discard acquired values from specific entries in the
channel list. You can enable or disable inhibition for each entry in the analog input channel
list. If enabled, the value is discarded after the channel is read; if disabled, the value is not
discarded after the channel is read.
Specifying Digital Input Lines in the Analog Input Channel List
In addition to the analog input channels, you can read the 16 digital I/O lines (Bank A 0 to 7
and Bank B 0 to 7) of the DT3034 boards using the analog input channel list. This feature is
particularly useful when you want to correlate the timing of analog and digital events.
To read these 16 digital I/O lines, specify channel 32 in the analog input channel list. You can
enter channel 32 anywhere in the list and can enter it more than once, if desired.
This channel is treated like any other channel in the analog input channel list; therefore, all the
clocking, triggering, and conversion modes supported for analog input channels are
supported for these digital I/O lines, if you specify them in this manner.
Performing Dynamic Digital Output Operations
Note: This feature is supported in the DataAcq SDK. It is not supported in the DT-Open
Layers for .NET Class Library.
Using software, you can enable a synchronous dynamic digital output operation for the A/D
subsystem. This feature is particularly useful for synchronizing and controlling external
equipment.