Table 6. LED State/Thermocouple Status
LED Color and State
Thermocouple Status
Red, solid
Open thermocouple detected
Green, solid
Thermocouple connected
Yellow, blinking/
alternating
User-defined status. Use MAX to write a state to any LED by
expanding
Devices and Interfaces
»
Network Devices
»
your
FieldDAQ device
»
bank of connectors in your FieldDAQ
device
and configuring the LED settings on the Settings tab.
Note
When you turn off the LEDs in MAX, the FieldDAQ device controls and sets
the state of the LED. You cannot configure an LED while a task is running.
Thermocouple Connection Guidelines
The following figure shows a general connection diagram.
Figure 10. Connection Diagram
Thermocouple
TC-
TC+
Notice
To protect against ESD, water, and dirt, install FD-11940, Mini-TC
Connector Protection Boot (Qty 8) (NI part number 786394-01) on the mini-TC
plugs.
Make sure that devices you connect to the FD-11613 are compatible with the device
specifications. Refer to your thermocouple documentation or the thermocouple wire spool to
determine which wire is the positive lead and which wire is the negative lead.
Minimizing Thermal Gradients
Changes in the ambient air temperature near the front connector or a thermocouple wire
conducting heat directly to terminal junctions can cause thermal gradients. Observe the
following guidelines to minimize thermal gradients and improve the system accuracy.
•
Use small-gauge thermocouple wire. Smaller wire transfers less heat to or from the
terminal junction.
•
Run thermocouple wiring together to keep the wires at the same temperature.
•
Avoid running thermocouple wires near hot or cold objects.
•
Minimize adjacent heat sources and air flow across the terminals.
•
Keep the ambient temperature as stable as possible.
•
Make sure the FieldDAQ device terminals are facing forward or upward.
•
Keep the FieldDAQ device in a stable and consistent orientation.
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FD-11613 User Guide