Wiring and Noise Reduction Methods
363
HP E1415 Guard
Connections
The HP E1415 guard connection provides a 10 K
Ω
current limiting resistor
between the guard terminals (G) and E1415 chassis ground for each 8
channel SCP bank. This is a safety device for the case where the Device
Under Test (DUT) isn’t actually floating, the shield is connected to the DUT
and also connected to the HP E1415 guard terminal (G). The 10 K
Ω
resistor
limits the ground loop current, which has been known to burn out shields.
This also provides 20 K
Ω
isolation between shields between SCP banks
which helps isolate the noise source.
Common Mode
Voltage Limits
You must be very careful not to exceed the maximum common mode
voltage referenced to the card chassis ground of
±
16 volts (
±
60 volts with
the HP E1513A Attenuator SCP). There is an exception to this when high
frequency (1 kHz - 20 kHz) common mode noise is present (see “HP E1415
Noise Rejection” below). Also, if the DUT is not grounded, then the shield
should be connected to the E1415 chassis ground.
When to Make
Shield Connections
It is not always possible to state positively the best shield connection for all
cases. Shield performance depends on the noise coupling mechanism which
is very difficult to determine. The above recommendations are usually the
best wiring method, but if feasible, experiment with shield connections to
determine which provides the best performance for your installation and
environment.
NOTE
For a thorough, rigorous discussion of measurement noise, shielding, and
filtering, see “Noise Reduction Techniques in Electronic Systems” by Henry
W. Ott of Bell Laboratories, published by Wiley & Sons, ISBN
0-471-85068-3.
Noise Due to Inadequate Card Grounding
If either or both of the HP E1415 and HP E1482 (MXI Extender Modules)
are not securely screwed into the VXIbus Mainframe, noise can be
generated. Make sure that both screws (top and bottom) are screwed in tight.
If not, it is possible that CVT data could be more noisy than FIFO data
because the CVT is located in A24 space, the FIFO in A16 space; more lines
moving could cause noisier readings.
Содержание VXI 75000 C Series
Страница 2: ......
Страница 16: ...16 ...
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Страница 30: ...30 Getting Started Chapter 1 Notes ...
Страница 32: ...32 Field Wiring Chapter 2 Figure 2 1 Channel Numbers at SCP Positions ...
Страница 44: ...44 Field Wiring Chapter 2 Figure 2 11 HP E1415 Terminal Module ...
Страница 54: ...54 Field Wiring Chapter 2 Notes ...
Страница 61: ...Programming the HP E1415 for PID Control 61 Chapter 3 Programming Overview Diagram ...
Страница 124: ...124 Creating and Running Custom Algorithms Chapter 4 Figure 4 2 Algorithm Operating Sequence Diagram ...
Страница 136: ...136 Creating and Running Custom Algorithms Chapter 4 Notes ...
Страница 152: ...152 Algorithm Language Reference Chapter 5 Notes ...
Страница 304: ...304 HP E1415 Command Reference Chapter 6 Command Quick Reference Notes ...
Страница 308: ...308 Specifications Appendix A Thermocouple Type E 200 800C SCPs HP E1501 02 03 ...
Страница 309: ...Specifications 309 Appendix A Thermocouple Type E 200 800C SCPs HP E1508 09 ...
Страница 310: ...310 Specifications Appendix A Thermocouple Type E 0 800C SCPs HP E1501 02 03 ...
Страница 311: ...Specifications 311 Appendix A Thermocouple Type E 0 800C SCPs HP E1509 09 ...
Страница 312: ...312 Specifications Appendix A Thermocouple Type E Extended SCPs HP E1501 02 03 ...
Страница 313: ...Specifications 313 Appendix A Thermocouple Type E Extended SCPs HP E1508 09 ...
Страница 314: ...314 Specifications Appendix A Thermocouple Type J SCPs HP E1501 02 03 ...
Страница 315: ...Specifications 315 Appendix A Thermocouple Type J SCPs HP E1508 09 ...
Страница 316: ...316 Specifications Appendix A Thermocouple Type K SCPs HP E1501 02 03 ...
Страница 317: ...Specifications 317 Appendix A Thermocouple Type R SCPs HP E1501 02 03 ...
Страница 318: ...318 Specifications Appendix A Thermocouple Type R SCPs HP E1508 09 ...
Страница 319: ...Specifications 319 Appendix A Thermocouple Type S SCPs HP E1501 02 03 ...
Страница 320: ...320 Specifications Appendix A Thermocouple Type S SCPs HP E1508 09 ...
Страница 321: ...Specifications 321 Appendix A Thermocouple Type T SCPs HP E1501 02 03 ...
Страница 322: ...322 Specifications Appendix A Thermocouple Type T SCPs HP E1508 09 ...
Страница 323: ...Specifications 323 Appendix A 5K Thermistor Reference SCPs HP E1501 02 03 ...
Страница 324: ...324 Specifications Appendix A 5K Thermistor Reference SCPs HP E1508 09 ...
Страница 325: ...Specifications 325 Appendix A RTD Reference SCPs HP E1501 02 03 ...
Страница 326: ...326 Specifications Appendix A RTD SCPs HP E1501 02 03 ...
Страница 327: ...Specifications 327 Appendix A RTD SCPs HP E1508 09 ...
Страница 328: ...328 Specifications Appendix A 2250 Thermistor SCPs HP E1501 02 03 ...
Страница 329: ...Specifications 329 Appendix A 2250 Thermistor SCPs HP E1508 09 ...
Страница 330: ...330 Specifications Appendix A 5K Thermistor SCPs HP E1501 02 03 ...
Страница 331: ...Specifications 331 Appendix A 5K Thermistor SCPs HP E1508 09 ...
Страница 332: ...332 Specifications Appendix A 10K Thermistor SCPs HP E1501 02 03 ...
Страница 333: ...Specifications 333 Appendix A 10K Thermistor SCPs HP E1508 09 ...
Страница 334: ...334 Specifications Appendix A Notes ...
Страница 346: ...346 Glossary Appendix C Notes ...
Страница 388: ...388 Generating User Defined Functions Appendix F Notes ...
Страница 438: ...438 Index Writing the algorithm 129 values to CVT elements 120 values to the FIFO 121 Z ZERO CALibration ZERO 194 ...