Measurement Computing UL for NI LabVIEW - Manual (Page 37)

Universal Library Virtual Instruments (VIs) Analog Input VIs
ErrCode Error code returned from the Universal Library. Zero if no error occurred. Use the
ErrMsg VI to convert ErrCod e into a readable string.
A/D Range – IMPORTANT
If an EXP board is connected to an A/D board that does not have programmable gain then the A/D board input
range is read from the configuration file (CB.CFG). In most cases, hardware-selectable ranges should be set
for ±5 V for thermocouples and 0 to 10 V for RTDs. If the board does have programmable gains, the
TInScan.VI will set the appropriate A/D range. Refer to the board-specific information for details.
Note on CJC Channel: The CJC channel is set in the install program. If you have multiple EXP boards, the
LabVIEW VI will apply the CJC reading to the linearization formula in the following manner:
ƒ If you have chosen a CJC channel for the EXP board that the channel you are reading is on, it will use the
CJC temp reading from that board.
ƒ If you have left the CJC channel for the EXP board that the channel you are reading is on to NOT SET,
the VI will use the CJC reading from the next lower EXP board with a CJC channel selected.
For example: Assume you have four CIO-EXP16 boards connected to a PCI-DAS08 on channel 0, 1, 2,
and 3, and you have chosen CIO-EXP16 #1 (connected to PCI-DAS08 channel 0) to have its CJC read on
PCI-DAS08 channel 7.
ƒ If you have left CIO-EXP16 CJC channels 2, 3, and 4 to NOT SET, those CIO-EXP boards will all use
the CJC reading from CIO-EXP16 #1, connected to channel 7 for linearization.
Note that it is important to keep the CIO-EXP boards in the same case and out of any breezes to ensure valid
CJC readings.
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