Campbell Scientific CR6 CR6 Measurement and Control System - Page 257

Demonstration Program

Page 257 highlights

Section 7. Installation 7.9.16.5.6 • String declarations: String variables are memory intensive. Determine how large strings are and declare variables just large enough to hold the string. If the sensor sends multiple strings at once, consider declaring a single string variable and read incoming strings one at a time. The CR6 adjusts the declared size of strings. One byte is always added to the declared length, which is then increased by up to another three bytes to make length divisible by four. Declared string length, not number of characters, determines the memory consumed when strings are written to memory. Consequently, large strings not filled with characters waste significant memory. Demonstration Program Caution - The following feature or information pertains to the CR6 datalogger in concept only. It is not yet adapted to CR6 specifics. CRBasic example Receiving an RS-232 String (p. 257) is provided as an exercise in serial input / output programming. The example only requires the CR6 and a single-wire jumper between COM1 Tx and COM2 Rx. The program simulates a temperature and relative humidity sensor transmitting RS-232 (simulated data comes out of COM1 as an alpha-numeric string). CRBasic Example 53. Receiving an RS-232 String ' CR6 serial I/O features by: ' 1. Simulating a serial sensor ' 2. Transmitting a serial string via COM1 TX. 'The serial string is received at COM2 RX via jumper wire. Simulated 'air temperature = 27.435 F, relative humidity = 56.789 %. 'Wiring: 'COM1 TX (C1) ----- COM2 RX (C4) 'Serial Out Declarations Public TempOut As Float Public RhOut As Float 'Declare a string variable large enough to hold the output string. Public SerialOutString As String * 25 'Serial In Declarations 'Declare a string variable large enough to hold the input string Public SerialInString As String * 25 'Declare strings to accept parsed data. 'array can be declared as Float or Long Public InStringSplit(2) As String Alias InStringSplit(1) = TempIn Alias InStringSplit(2) = RhIn If parsed data are strictly numeric, this 257

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Section 7.
Installation
String declarations:
String variables are memory intensive. Determine how
large strings are and declare variables just large enough to hold the string. If
the sensor sends multiple strings at once, consider declaring a single string
variable and read incoming strings one at a time.
The CR6 adjusts the declared size of strings. One byte is always added to the
declared length, which is then increased by up to another three bytes to make
length divisible by four.
Declared string length, not number of characters, determines the memory
consumed when strings are written to memory. Consequently, large strings
not filled with characters waste significant memory.
7.9.16.5.6
Demonstration Program
Caution
— The following feature or information pertains to the CR6 datalogger
in concept only.
It is not yet adapted to CR6 specifics.
CRBasic example
Receiving an RS-232 String
(p. 257)
is provided as an exercise in
serial input / output programming.
The example only requires the CR6 and a
single-wire jumper between
COM1 Tx
and
COM2 Rx
. The program simulates a
temperature and relative humidity sensor transmitting RS-232 (simulated data
comes out of
COM1
as an alpha-numeric string).
CRBasic Example 53.
Receiving an RS-232 String
'<TPED> CR6 serial I/O features by:
'
1. Simulating a serial sensor
'
2. Transmitting a serial string via COM1 TX.
'The serial string is received at COM2 RX via jumper wire.
Simulated
'air temperature = 27.435 F, relative humidity = 56.789 %.
'Wiring:
'COM1 TX (C1) ----- COM2 RX (C4)
'Serial Out Declarations
Public
TempOut
As Float
Public
RhOut
As Float
'Declare a string variable large enough to hold the output string.
Public
SerialOutString
As String
* 25
'Serial In Declarations
'Declare a string variable large enough to hold the input string
Public
SerialInString
As String
* 25
'Declare strings to accept parsed data.
If parsed data are strictly numeric, this
'array can be declared as Float or Long
Public
InStringSplit(2)
As String
Alias
InStringSplit(1) = TempIn
Alias
InStringSplit(2) = RhIn
257