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Chapter 4 Features and Functions
34908A 40-Channel Single-Ended Multiplexer
4
34908A 40-Channel Single-Ended Multiplexer
The module is divided into two banks of 20 channels each. All of the 40
channels switch HI only, with a common LO for the module. The module
has a built-in thermocouple reference junction to minimize errors due to
thermal gradients when measuring thermocouples.
NOTES:
•
Refer to the diagrams on page 27 to connect wiring to the module.
•
Only one channel can be closed at a time; closing one channel will open the previously
closed channel.
•
This module cannot be used to directly measure current or any 4-wire measurements.
•
When connecting thermocouples to the screw terminals on this module (not recommended
due to the common LO configuration), be sure to provide electrical isolation between
thermocouples to avoid current loops and subsequent measurement errors.
•
Connections to AC line are not recommended unless you provide external transient
Maximum Input Voltage: 300 V (CAT I)
Maximum Input Current: 1 A
Maximum Switching Power: 50 W
WARNING: To prevent electrical shock, use only wire that is rated for the highest voltage
applied to any channel. Before removing a module cover, turn off all power to external devices
connected to the module.
Bank Switch
Channel Switches
Backplane
Internal
DMM Input
Reference
Junction
Sensor
01
20
Com
21
40
98
99
Switch
Com
6mm
20 AWG Typical
34970A Refresh UG.book Page 213 Wednesday, February 17, 2010 12:34 PM
Содержание 34970A
Страница 16: ...16 34970A Refresh UG book Page 16 Wednesday February 17 2010 12 34 PM ...
Страница 20: ...34970A Refresh UG book Page 20 Wednesday February 17 2010 12 34 PM ...
Страница 21: ...1 1 Quick Start 34970A Refresh UG book Page 21 Wednesday February 17 2010 12 34 PM ...
Страница 39: ...2 2 Front Panel Overview 34970A Refresh UG book Page 39 Wednesday February 17 2010 12 34 PM ...
Страница 59: ...3 3 System Overview 34970A Refresh UG book Page 59 Wednesday February 17 2010 12 34 PM ...
Страница 87: ...4 4 Features and Functions 34970A Refresh UG book Page 87 Wednesday February 17 2010 12 34 PM ...
Страница 217: ...5 5 Error Messages 34970A Refresh UG book Page 217 Wednesday February 17 2010 12 34 PM ...
Страница 240: ...240 Chapter 5 Error Messages Plug In Module Errors 34970A Refresh UG book Page 240 Wednesday February 17 2010 12 34 PM ...
Страница 241: ...6 6 Application Programs 34970A Refresh UG book Page 241 Wednesday February 17 2010 12 34 PM ...
Страница 254: ...254 34970A Refresh UG book Page 254 Wednesday February 17 2010 12 34 PM ...
Страница 255: ...7 7 Tutorial 34970A Refresh UG book Page 255 Wednesday February 17 2010 12 34 PM ...
Страница 324: ...324 34970A Refresh UG book Page 324 Wednesday February 17 2010 12 34 PM ...