Section 7. Installation
181
SDI12Recorder
(Temp(3),1,2,"M!",1.0,0)
SDI12Recorder
(Temp(4),1,3,"M!",1.0,0)
NextScan
EndSequence
EndProg
However, problems 2 and 3 still are not resolved. These can be resolved by using
the concurrent measurement command,
C!
. All measurements will be made at
about the same time and execution time will be about 95 seconds, well within the
5-minute scan rate requirement, as follows:
Public
BatteryVolt
Public
Temp(4)
BeginProg
Scan
(5,Sec,0,0)
'Non-SDI-12 measurements here
NextScan
SlowSequence
Scan
(5,Min,0,0)
SDI12Recorder
(Temp(1),1,0,"C!",1.0,0)
SDI12Recorder
(Temp(2),1,1,"C!",1.0,0)
SDI12Recorder
(Temp(3),1,2,"C!",1.0,0)
SDI12Recorder
(Temp(4),1,3,"C!",1.0,0)
NextScan
EndProg
A new problem introduced by the
C!
command, however, is that it causes high
power usage by the CR800. This application has a very tight power budget.
Since the
C!
command reissues a measurement request immediately after
receiving data, the sensors will be in a high power state continuously. To remedy
this problem, measurements need to be started with
C!
command, but stopped
short of receiving the next measurement command (hard-coded part of the
C!
routine) after their data are polled. The
SDI12Recorder()
instruction
C
command
(not
C!
) provides this functionality as shown in CRBasic example
Using Alternate
Concurrent Command (aC)
(p. 182).
A modification of this program can also be
used to allow near-simultaneous measurement of SDI-12 sensors without
requesting additional measurements, such as may be needed in an event-driven
measurement.
Note
When only one SDI-12 sensor is attached, that is, multiple sensor
measurements do not need to start concurrently, another reliable method for
making SDI-12 measurements without affecting the main scan is to use the
CRBasic
SlowSequence
instruction and the SDI-12
M!
command. The main
scan will continue to run during the
ttt
time returned by the SDI-12 sensor. The
trick is to synchronize the returned SDI-12 values with the main scan.
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: ......