Section 7. Installation
85
Table 4.
Current Source and Sink Limits
Terminal
Limit
1
< 1.80 A @ 70°C
< 1.50 A @ 85°C
5V
+
CS I/O
(combined)
5
< 200 mA
1
"Source" is positive amperage; "sink" is negative amperage (-).
2
Exceeding current limits limits will cause voltage output to become unstable. Voltage should
stabilize once current is again reduced to within stated limits.
3
A polyfuse is used to limit power. Result of overload is a voltage drop. To reset, disconnect and
allow circuit to cool. Operating at the current limit is OK so long a a little fluctuation can be
tolerated.
4
Polyfuse protected. See footnote 3.
5
Current is limited by a current limiting circuit, which holds the current at the maximum by
dropping the voltage when the load is too great.
7.4.5.1 Switched Voltage Excitation
Two switched, analog-output (excitation) terminals (
VX1
-
VX2
) operate under
program control to provide -2500 mVdc to +2500 mVdc excitation. Check the
accuracy specification of these channels in CR800 Specifications
to understand
their limitations. Specifications are only applicable for loads not exceeding ±25
mA.
Note
Table
Current Source and Sink Limits
(p. 84)
has more information on
excitation load capacity.
CRBasic instructions that control excitation channels include:
•
BrFull
()
•
BrFull6W
()
•
BrHalf
()
•
BrHalf3W
()
•
BrHalf4W
()
•
ExciteV
()
Note
Excitation channels can be configured to provide a square-wave ac
excitation for use with polarizing bridge sensors through the
RevEx
parameter of
the previously listed bridge instructions.
7.4.5.2 Continuous Regulated (5 Volt)
The
5V
terminal is regulated and remains near 5 Vdc (
±
4%) so long as the CR800
supply voltage remains above 9.6 Vdc. It is intended for power sensors or devices
requiring a 5-Vdc power supply. It is not intended as an excitation source for
bridge measurements. However, measurement of the
5V
terminal output, by
means of jumpering to an analog input on the same CR800), will facilitate an
accurate bridge measurement if
5V
must be used.
Содержание CR850
Страница 2: ......
Страница 4: ......
Страница 6: ......
Страница 26: ...Table of Contents 26...
Страница 30: ...Section 2 Cautionary Statements 30...
Страница 32: ...Section 3 Initial Inspection 32...
Страница 35: ...Section 4 Quickstart Tutorial 35 Figure 2 Wiring panel...
Страница 55: ...Section 4 Quickstart Tutorial 55 Figure 24 PC200W View data utility...
Страница 78: ...Section 5 System Overview 78...
Страница 80: ...Section 6 CR800 Specifications 80...
Страница 95: ...Section 7 Installation 95 Figure 35 DevConfig OS download window Figure 36 Dialog box confirming OS download...
Страница 104: ...Section 7 Installation 104 Figure 43 Include File settings via DevConfig Figure 44 Include File settings via PakBusGraph...
Страница 267: ...Section 7 Installation 267 Figure 84 Running average signal attenuation...
Страница 268: ...Section 7 Installation 268...
Страница 384: ...Section 8 Operation 384 Figure 113 Using the keyboard display...
Страница 385: ...Section 8 Operation 385 8 8 1 Data Display Figure 114 Displaying data with the keyboard display...
Страница 387: ...Section 8 Operation 387 Figure 116 Real time custom...
Страница 388: ...Section 8 Operation 388 8 8 1 3 Final Storage Tables Figure 117 Final storage tables...
Страница 389: ...Section 8 Operation 389 8 8 2 Run Stop Program Figure 118 Run Stop Program...
Страница 390: ...Section 8 Operation 390 8 8 3 File Display Figure 119 File display...
Страница 396: ...Section 8 Operation 396...
Страница 402: ...Section 9 Maintenance 402...
Страница 450: ...Section 11 Glossary 450...
Страница 504: ...Appendix A CRBasic Programming Instructions 504...
Страница 526: ...Appendix B Status Table and Settings 526...
Страница 530: ...Appendix C Serial Port Pinouts 530...
Страница 536: ...Appendix E FP2 Data Format 536...
Страница 550: ...Appendix F Other Campbell Scientific Products 550...
Страница 564: ...Index 564 WriteIO 464 Writing Program 108 X XML 448 XOR 473 Y Y intercept 141 142 Z Zero 155 166 Zero Basis 151...
Страница 565: ......