User`s guide

Universal Library User's Guide Analog Input Boards - USB-1616HS, USB-1616HS-2, and USB-1616HS-4
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ChanArray ANALOG: USB-1616HS-4: 0 to 3
USB-1616HS-2: 0 to 1
DIGITAL16: FIRSTPORTA (FIRSTPORTB must be configured as an output)
Rate ANALOG: Up to 1 MHz
DIGITAL16: Up to 12 MHz (system-dependent) if no analog channel is
selected. Otherwise up to 1 MHz.
Range BIP10VOLTS ( 10 V)
Hardware considerations
Associating CJC channels with TC channels
The TC channels must immediately follow their associated CJC channels in the channel array. For accurate
thermocouple readings, associate CJC channels with the TC channels as listed in the following table:
CJC channels
TC channels
CJC0
TC0
CJC1
TC1 and TC2
CJC2
TC3
CJC3
TC4
CJC4
TC5 and TC6
CJC5
TC7
When the AI-EXP48 board is installed:
CJC6
TC8 through TC11
CJC7
TC12 through TC15
CJC8
TC16 through TC19
CJC9
TC20 through TC23
CJC10
TC24 through TC27
CJC11
TC28 through TC31
The board must be configured for differential inputs when using thermocouples
TC inputs are supported by differential mode configuration only.
Channel count
For input and output scans, the count must be set to an integer multiple of the number of channels or a
BADCOUNT error is returned.
Sampling and update rates
Sampling and update rates are system-dependent. Data overruns/underruns may occur with higher sampling
rates when using BACKGROUND and CONTINUOUS modes. To avoid this, use a larger buffer/count size, or use
NONSTREAMEDIO mode, if supported. The minimum size buffer is 256 for cbAOutScan()/AOutScan(). Values
less than that result in a BADBUFFERSIZE error.
Settling time
For most applications, settling time should be left at the default value of 1 µs. However, if you are scanning
multiple channels and one or more channels are connected to a high impedance source, you may get better
results by increasing the settling time. Keep in mind that increasing the settling time reduces the maximum
acquisition rate. You can set the time between A/D conversions with the ADC Settling Time option in
InstaCal. Select between 1 µs, 5 µs, 10 µs, or 1 ms.