Programming the VT1422A for Data Acquisition and Control 111
Chapter 4
Linking Resistance
Measurements
To link channels to the resistance EU conversion send the
[SENSe:]FUNCtion:RESistance
<
excite_current
>,[<
range
>,](@<
ch_list
>) command.
Resistance measurements assume that there is at least one Current Source
SCP installed (eight current sources per SCP). See Figure 4-5.
•
The
<excite_current>
parameter is used only to tell the EU conversion
what the Current Source SCP channel is now set to.
<excite_current>
is specified in amps dc and the choices for the VT1505A SCP are
30e-6 (or MIN) and 488e-6 (or MAX). Select 488
µ
A for measuring
resistances of less than 8,000
Ω
. Select 30
µ
A for resistances of
8,000
Ω
and above.
•
The optional
<range>
parameter can be used to choose a fixed A/D
range. When not specified (defaulted), the module uses auto-range.
•
The
<ch_list>
parameter specifies which channel(s) to link to the
resistance EU conversion. These channels will sense the voltage across
the unknown resistance. Each can be a Current Source SCP channel
(a two-wire resistance measurement) or a sense channel separate from
the Current Source SCP channel (a four-wire resistance measurement).
See Figure 4-5 for diagrams of these measurement connections.
* Because of the 150 ohm resistor in series with each of the
current source outputs, Two-Wire resistance and temperature
measurements will have a 300 ohm offset.
** The current source Hi terminal is the negative voltage node.
The current source LO terminal is the positive voltage node.
Two-Wire Measurement
(not recommended **)
Current Source SCP
Field Wiring
Sens
e
C
h
annel
*150 ohm 5%
*150 ohm 5%
R
Four-Wire Measurement
Current Source SCP
Field Wiring
HI
LO
HI
LO
R
Any Sense SCP
Sens
e
C
h
annel
HI
LO
Figure 4-5. Resistance Measurement Sensing
Содержание VT1422A
Страница 2: ...This page is blank...
Страница 8: ...8 Notes...
Страница 22: ...22 Support...
Страница 57: ...Field Wiring 57 Chapter 2...
Страница 58: ...58 Field Wiring Chapter 2...
Страница 96: ...94 Programming the VT1422A VT1529A B for Remote Strain Measurement Chapter 3...
Страница 162: ...160 Programming the VT1422A for Data Acquisition and Control Chapter 4...
Страница 224: ...222 Creating and Running Algorithms Chapter 6...
Страница 419: ...VT1422A Command Reference 417 Chapter 7 Notes...
Страница 420: ...418 VT1422A Command Reference Chapter 7 Notes...
Страница 425: ...Specifications 423 Appendix A Thermocouple Type E 200 800 C SCPs VT1501 02 03A...
Страница 426: ...424 Specifications Appendix A Thermocouple Type E 200 800 C SCPs VT1508 09A...
Страница 427: ...Specifications 425 Appendix A Thermocouple Type E 0 800 C SCPs VT1501A 02A 03A...
Страница 428: ...426 Specifications Appendix A Thermocouple Type E 0 800 C SCPs VT1508A 09A...
Страница 429: ...Specifications 427 Appendix A Thermocouple Type E Extended SCPs VT1501A 02A 03A...
Страница 430: ...428 Specifications Appendix A Thermocouple Type E Extended SCPs VT1508A 09A...
Страница 431: ...Specifications 429 Appendix A Thermocouple Type J SCPs VT1501A 02A 03A...
Страница 432: ...430 Specifications Appendix A Thermocouple Type J SCPs VT1508A 09A...
Страница 433: ...Specifications 431 Appendix A Thermocouple Type K SCPs VT1501A 02A 03A...
Страница 434: ...432 Specifications Appendix A Thermocouple Type R SCPs VT1501A 02A 03A...
Страница 435: ...Specifications 433 Appendix A Thermocouple Type R SCPs VT1508A 09A...
Страница 436: ...434 Specifications Appendix A Thermocouple Type S SCPs VT1501A 02A 03A...
Страница 437: ...Specifications 435 Appendix A Thermocouple Type S SCPs VT1508A 09A...
Страница 438: ...436 Specifications Appendix A Thermocouple Type T SCPs VT1501A 02A 03A...
Страница 439: ...Specifications 437 Appendix A Thermocouple Type T SCPs VT1508A 09A...
Страница 440: ...438 Specifications Appendix A 5k Thermistor Reference SCPs VT1501A 02A 03A...
Страница 441: ...Specifications 439 Appendix A 5k Thermistor Reference SCPs VT1508A 09A...
Страница 442: ...440 Specifications Appendix A RTD Reference SCPs VT1501A 02A 03A...
Страница 443: ...Specifications 441 Appendix A RTD SCPs VT1501A 02A 03A...
Страница 444: ...442 Specifications Appendix A RTD SCPs VT1508A 09A...
Страница 445: ...Specifications 443 Appendix A 2250 Thermistor SCPs VT1501A 02A 03A...
Страница 446: ...444 Specifications Appendix A 2250 Thermistor SCPs VT1508A 09A...
Страница 447: ...Specifications 445 Appendix A 5k Thermistor SCPs VT1501A 02A 03A...
Страница 448: ...446 Specifications Appendix A 5k Thermistor SCPs VT1508A 09A...
Страница 449: ...Specifications 447 Appendix A 10k Thermistor SCPs VT1501A 02A 03A...
Страница 450: ...448 Specifications Appendix A 10k Thermistor SCPs VT1508A 09A...
Страница 454: ...452 Specifications Appendix A...
Страница 480: ...478 VT1529A B Verification Calibration Appendix C...
Страница 484: ...482 Glossary Appendix D Notes...