FP-TC-120 and cFP-TC-120
12
ni.com
Thermocouple wire can also be a significant source of thermal
gradients. Even the FP-TB-3 and cFP-CB-3 can be susceptible to
these errors. Heat or cold may be directly conducted to the terminal
junction by the thermocouple wire. If the thermocouple wires,
or objects they are in contact with, such as wiring ducts, near the
terminal base are at a different temperature than the terminals,
the wires transfer heat to or from the terminals and cause thermal
errors. To minimize these errors, follow these guidelines:
•
Use small-gauge thermocouple wire. Smaller wire transfers
less heat.
•
Run thermocouple wiring together near the terminal base to
keep the wires at the same temperature.
•
Avoid running thermocouple wires near hot or cold objects.
•
If you connect any extension wires to thermocouple wires,
use wires made of the same conductive material.
Status Indicators
Figure 9 shows the [c]FP-TC-120 status indicators.
Figure 9.
Status Indicators
The [c]FP-TC-120 has two green status LEDs,
POWER
and
READY
. After you insert the [c]FP-TC-120 into a terminal base
or backplane and apply power to the connected network module,
the green
POWER
indicator lights and the [c]FP-TC-120 informs
the network module of its presence. When the network module
recognizes the [c]FP-TC-120, it sends initial configuration
information to the [c]FP-TC-120. After receiving this initial
information, the green
READY
indicator lights and the
[c]FP-TC-120 is in normal operating mode.
In addition to the green
POWER
and
READY
indicators, the
[c]FP-TC-120 has eight red open-thermocouple LEDs labeled
0
to
7
. When a channel that has been configured for temperature
measurements detects an open thermocouple, the red LED for that
channel lights.
