Programming The Fielddaq Device - National Instruments FD-11613 User Manual

• Allow the thermal gradients to settle after a change in system power or in ambient
temperature. A change in system power can happen when the system powers on, or you
add or remove devices from a network topology.
• Allow the thermal gradients to settle after plugging or unplugging the mini-TC plugs.
Thermocouple Measurement Accuracy
Thermocouple measurement errors depend partly on the following factors:
• Type of thermocouple
• Accuracy of the thermocouple
• Temperature that you are measuring
• Resistance of the thermocouple wires
• Cold-junction temperature
For the best accuracy performance, set up the FD-11613 according to
Device and Thermocouple Connection Guidelines
terminals.

Programming the FieldDAQ Device

You can use the FieldDAQ device in the following analog input applications:
• Single-point acquisition
• Finite acquisition
• Continuous acquisition
The FieldDAQ device features the following timing and triggering signals:
• AI Sample Clock Signal
• AI Sample Clock Timebase Signal
• AI Start Trigger Signal
For more information about programming analog input applications and triggers in software,
refer to the NI-DAQmx Help or the LabVIEW Help for more information.
AI Sample Clock Signal
A sample consists of one reading from each channel in the AI task. Sample Clock signals the
start of a sample of all analog input channels in the task. Refer to the following figure for
sample clock source options.
80 MHz Timebase
20 MHz Timebase
100 kHz Timebase
Figure 11. AI Sample Clock Timing Options
AI Sample Clock
Timebase
Setting up the FieldDAQ
to minimize thermal gradients across the
Programmable
Clock
Divider
FD-11613 User Guide | © National Instruments | 17
AI Sample
Clock