AppendixC CommonQuestions
ATE Series User Manual C-6 ni.com
nextchannel, for example channel 1, is selected, the accumulated charge
(current) leaks backward through that channel. If the output impedance of
thesource connected to channel 1 is high enough, the resulting reading can
somewhatreflect the voltage trends in channel 0. To circumvent this
problem,you must use a voltage follower (op-amp with unity gain) for each
highimpedance source before connecting up to the DAQ device or decrease
the rateat w hich each channel issampled. Another common cause of
channelcrosstalk i sdue to sampling among multiple channels at various
gains. In this situation, the settling times may increase. For more
information oncharge injection and sampling channels at different gains,
referto Chap ter 3, Hardware Overview.
How arethe AI c hannels of the AT-MIO-64E-3addressed when they
areusedindifferentialmode?
The 32 differentialchannel pairs are addressed as shown in the following
table.
Howcan I use STARTSCAN and CONVERT* on my device to sample
my AI channel(s)?
An Es eriesd eviceemploys both the STARTSCAN and CONVERT*
signals to perform intervalsam pling. The STARTSCANsignal of the
DAQ-STCcontrols the scan interval (1/scan interval = scan rate) shown
in Figure C-2. The CONVERT*signal controls the interchannel delay
(1/interchannel delay = sampling rate). This method allows multiple
channelsto be sampled relatively quickly in relationship to the overall scan
rateproviding a pseudo simultaneous effect with a fixed delay between
channels.
DifferentialChannel Name I/OTerminals
<0..7> ACH<0,8...7,15>
<16..23> ACH<16,24...23,31>
<32..39> ACH<32,40...39,47>
<44..58> ACH<48,56...55,63>