Campbell Scientific CR6 CR6 Measurement and Control System - Page 254

SerialOpen, SerialIn, SerialInRecord, SplitStr

Page 254 highlights

Section 7. Installation 254 1. Know what the sensor supports and exactly what the data are. Most sensors work well with TTL voltage levels and RS-232 logic. Some things to consider: • Become thoroughly familiar with the data to be captured. • Can the sensor be polled? • Does the sensor send data on its own schedule? • Are there markers at the beginning or end of data? Markers are very useful for identifying a variable length record. • Does the record have a delimiter character, e.g. ",", spaces, or tabs? These delimiters are useful for parsing the record into usable numbers. • Will the sensor be sending multiple data strings? Multiple strings usually require filtering before parsing. • How fast will data be sent to the CR6? • Is power consumption critical? • Does the sensor compute a checksum? Which type? A checksum is useful to test for data corruption. 2. Open a serial port (SerialOpen() instruction). • Example: SerialOpen(Com1,9600,0,0,10000) • Designate the correct port in CRBasic. • Correctly wire the device to the CR6. • Match the port baud rate to the baud rate of the device in CRBasic. o Use a fixed baud rate (rather than autobaud) when possible. 3. Receive serial data as a string (CRBasic SerialIn() or SerialInRecord() command). • Example: SerialInRecord(Com2,SerialInString,42,0,35,"",01) • Declare the string variable large enough to accept the string. o Example: Public SerialInString As String * 25 • Observe the input string in the input string variable in software numeric monitor. Note SerialIn() and SerialInRecord() receive the same data. SerialInRecord() is generally used for data streaming into the CR6, while SerialIn() is used for data that is received in discrete blocks. 4. Parse (split up) the serial string (CRBasic SplitStr() command). • Separates string into numeric and / or string variables. • Example: SplitStr(InStringSplit,SerialInString,"",2,0) • Declare an array to accept the parsed data. o Example: Public InStringSplit(2) As String

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Section 7.
Installation
1.
Know what the sensor supports and exactly what the data are.
Most sensors
work well with TTL voltage levels and RS-232 logic.
Some things to
consider:
Become thoroughly familiar with the data to be captured.
Can the sensor be polled?
Does the sensor send data on its own schedule?
Are there markers at the beginning or end of data? Markers are very useful
for identifying a variable length record.
Does the record have a delimiter character, e.g. ",", spaces, or tabs? These
delimiters are useful for parsing the record into usable numbers.
Will the sensor be sending multiple data strings? Multiple strings usually
require filtering before parsing.
How fast will data be sent to the CR6?
Is power consumption critical?
Does the sensor compute a checksum? Which type? A checksum is useful to
test for data corruption.
2. Open a serial port (
SerialOpen()
instruction).
Example:
SerialOpen
(Com1,9600,0,0,10000)
Designate the correct port in CRBasic.
Correctly wire the device to the CR6.
Match the port baud rate to the baud rate of the device in CRBasic.
o
Use a fixed baud rate (rather than autobaud) when possible.
3.
Receive serial data as a string (CRBasic
SerialIn()
or
SerialInRecord()
command).
Example:
SerialInRecord
(Com2,SerialInString,42,0,35,"",01)
Declare the string variable large enough to accept the string.
o
Example:
Public
SerialInString
As String
* 25
Observe the input string in the input string variable in software numeric
monitor.
Note
SerialIn()
and
SerialInRecord()
receive the same data.
SerialInRecord()
is generally used for data streaming into the CR6, while
SerialIn()
is used for
data that is received in discrete blocks.
4.
Parse (split up) the serial string (CRBasic
SplitStr()
command).
Separates string into numeric and / or string variables.
Example:
SplitStr
(InStringSplit,SerialInString,"",2,0)
Declare an array to accept the parsed data.
o
Example:
Public
InStringSplit(2)
As String
254