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4 inserting string characters, 5 extracting string characters, 6 string use of ascii / ansii codes – Campbell Scientific CR800 and CR850 Measurement and Control Systems User Manual

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Section 7. Installation

240 

 

 

Some smart sensors send strings containing NULL characters. To manipulate a
string that has NULL characters within it (in addition to being terminated with
another NULL), use MoveBytes() instruction.

7.8.13.4 Inserting String Characters

CRBasic Example 48. Inserting String Characters 

Objective:
Use MoveBytes() to change "123456789" to "123A56789"

Given:

StringVar(7) = "123456789"

'Result is

"123456789"

Try (does not work):

StringVar(7,1,4) = "A"

'Result is

"123A56789"

Instead, use:

StringVar(7) = MoveBytes(Strings(7,1,4),0,"A",0,1)

'Result is

"123A56789"

 

7.8.13.5 Extracting String Characters

A specific character in the string can be accessed by using the "dimensional"
syntax; that is, when the third dimension of a string is specified, the third
dimension is the character position.

Table 41. Extracting String Characters

Expression Comments

Result

StringVar(3) = "Go Jazz"

Loads string into variable

StringVar(3) = "Go Jazz"

StringVar(4) = StringVar(3,1,4)

Extracts single character

StringVar(4) = "J"

 

7.8.13.6 String Use of ASCII / ANSII Codes

Table 42. Use of ASCII / ANSII Codes Examples

Expression Comments

Result

LongVar (7) = ASCII("#")

35

LongVar (8) = ASCII("*")

42

LongVar (9) = "#"

Cannot be converted to Long with
NULL

NAN

LongVar (1) = "#"-""

Can be converted to Long without
NULL

35