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FP-TC-120 and cFP-TC-120

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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.

Содержание CFP-TC-120

Страница 1: ...P TC 120 and cFP TC 120 thermocouple input modules referred to inclusively as the c FP TC 120 For details on configuring and accessing the c FP TC 120 over a network refer to the user manual for the FieldPoint network module you are using Features The c FP TC 120 is a FieldPoint thermocouple input module with the following features Eight thermocouple or millivolt inputs Built in linearization and ...

Страница 2: ...the terminal base 3 Press firmly to seat the FP TC 120 on the terminal base The latch on the terminal base locks the FP TC 120 into place when it is firmly seated Figure 1 Installing the FP TC 120 Installing the cFP TC 120 The cFP TC 120 mounts on a FieldPoint backplane cFP BP x Hot plug and play enables you to install the cFP TC 120 onto a powered backplane without disturbing the operation of oth...

Страница 3: ...the c FP TC 120 The FP TB x terminal bases have connections for each of the eight differential input channels on the FP TC 120 and a common COM terminal for connecting a shield to each channel The cFP CB x connector blocks provide the same connections for the cFP TC 120 Table 1 lists the terminal assignments for the signals associated with each channel The terminal assignments are the same for the...

Страница 4: ...ng the C and COM terminals of the c FP TC 120 to the V C or COM terminals of another FieldPoint module defeats the isolation barriers between the two modules Taking Measurements with the c FP TC 120 The c FP TC 120 has eight differential input channels All eight channels share a common ground reference that is isolated from other modules in the FieldPoint system Each of the input channels has a bi...

Страница 5: ...the shield to the COM terminal Figure 4 shows a millivolt source connected to one channel of the c FP TC 120 Figure 4 Connecting a Millivolt Source to the c FP TC 120 The input ranges for the voltage inputs are 25 50 100 and 20 to 80 mV An input signal outside the selected input range causes the c FP TC 120 to report an Out of range error for the affected channel The c FP TC 120 ignores any config...

Страница 6: ...onnecting a Shielded Thermocouple to the c FP TC 120 The c FP TC 120 linearizes the thermocouple voltage and returns a reading in units of temperature The available ranges are 0 to 2 048 K 270 to 1 770 C and 454 to 3 218 F Temperatures outside these ranges result in an Out of range error for the affected channels Note You must configure each channel of the c FP TC 120 for the type of thermocouple ...

Страница 7: ... voltage source with a source impedance of 1 kΩ has an additional offset error of 35 µV and an additional gain error of 50 ppm Cold Junction Compensation Connecting thermocouple leads to the terminal base or connector block creates new thermocouple junctions between the thermocouple wires and the terminals These cold junctions affect the measured readings of the thermocouple The c FP TC 120 automa...

Страница 8: ...the setting of the CJC Source attribute CJ Temperature continues to reflect the actual measured temperature of the terminal base or connector block This method of software cold junction compensation is sufficient for applications in which temperatures are fairly stable and uniform across the system Determining Measurement Accuracy and Minimizing Errors It is difficult to define temperature measure...

Страница 9: ...ure gradient across the terminal base or connector block and do not include the accuracy of the thermocouple itself Figure 6 Type R and S Errors Figure 7 Type J K N T and E Errors 0 0 5 1 1 5 2 2 5 3 3 5 4 4 5 0 300 600 900 1200 1500 1800 300 Max Over Temp Max at Room Temp Typ Over Temp Typ at Room Temp Measured Temperature C Error C 0 0 5 1 1 5 2 2 5 3 3 5 4 5 5 0 300 600 900 1200 1500 1800 300 4...

Страница 10: ... 0 36 F gradient The actual gradient you can expect to encounter depends on the terminal base or connector block you use and the details of your installation The following sections provide guidelines for estimating and minimizing thermal gradients when using the FP TB x terminal bases If you are using the cFP CB x connector block refer to the cFP CB x Compact FieldPoint Connector Blocks Operating ...

Страница 11: ...cross the terminals of the FP TB 1 which you can estimate by dividing the larger of the amounts of heat dissipated by each of the adjacent modules by 1 W C 0 6 W F For example if the FP TB 1 2 is between an analog input module dissipating 0 35 W and a discrete output module dissipating 3 W the thermal gradient would be 3 W 1 W C 3 C The typical thermal gradient created by the FP TC 120 mounted on ...

Страница 12: ...ects 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 indicato...

Страница 13: ...C 61010 1 for working voltages of 250 Vrms 1 Safety standards such as those published by UL and IEC require the use of double insulation between hazardous voltages and any human accessible parts or circuits Never try to use any isolation product between human accessible parts such as DIN rails or monitoring stations and circuits that can be at hazardous potentials under normal conditions unless th...

Страница 14: ...that prevents accidental or unauthorized access to wiring that carries hazardous voltages The isolation of the c FP TC 120 is certified as double insulated for working voltages of 250 Vrms Do not use the c FP TC 120 as the only isolating barrier between human contact and working voltages of more than 250 Vrms Operate the c FP TC 120 only at or below pollution degree 2 Pollution degree 2 means that...

Страница 15: ...curacy 0 15 C typ 0 3 C max There is typically an additional 0 2 C difference between the temperature of the cold junction sensor and that of the actual terminals Update rate Each channel is updated every 1 13 s Input Range Offset Error 15 to 35 C Offset Error 40 70 C 25 mV 3 µV typ 5 µV max 4 5 µV typ 13 µV max 50 mV 3 5 µV typ 6 µV max 5 µV typ 13 µV max 100 mV 4 µV typ 7 µV max 5 5 µV typ 15 µV...

Страница 16: ...ical Indicators Two green LEDs for POWER and READY eight red LEDs for open thermocouple detected Weight FP TC 120 140 g 4 8 oz cFP TC 120 130 g 3 7 oz Power Requirements Power from network module 350 mW Isolation Voltage Isolation voltage rating 250 Vrms Installation Category II Channel to channel isolation No isolation between channels Transient overvoltage 2 300 Vrms Environmental FieldPoint mod...

Страница 17: ...quirements of the following standards for safety and electrical equipment for measurement control and laboratory use EN 61010 1 IEC 61010 1 UL 3121 1 CAN CSA c22 2 no 1010 1 Electromagnetic Compatibility CE C Tick and FCC Part 15 Class A Compliant Electrical emissions EN 55011 Class A at 10 m FCC Part 15A above 1 GHz Electrical immunity Evaluated to EN 61326 1997 A1 1998 Table 1 Note For full EMC ...

Страница 18: ... operating instructions Go to ni com support for the most current manuals examples and troubleshooting information For telephone support in the United States create your service request at ni com ask and follow the calling instructions or dial 512 795 8248 For telephone support outside the United States contact your local branch office Australia 03 9879 5166 Austria 0662 45 79 90 0 Belgium 02 757 ...

Страница 19: ... 0793 Netherlands 0348 433466 New Zealand 09 914 0488 Norway 32 27 73 00 Poland 22 3390 150 Portugal 210 311 210 Russia 095 238 7139 Singapore 65 6 226 5886 Slovenia 3 425 4200 South Africa 11 805 8197 Spain 91 640 0085 Sweden 08 587 895 00 Switzerland 056 200 51 51 Taiwan 02 2528 7227 United Kingdom 01635 523545 ...

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