7 parameter types, 1 expressions in parameters – Campbell Scientific CR5000 Measurement and Control Module User Manual

Page 85

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Section 4. CRBasic - Native Language Programming

4-9

4.7 Parameter Types

Instructions parameters allow different types of inputs these types are listed
below and specifically identified in the description of the parameter in the
following sections or in PC9000 CRBasic help.

Constant
Variable
Variable or Array
Constant, Variable, or Expression
Constant, Variable, Array, or Expression
Name
Name or list of Names
Variable, or Expression
Variable, Array, or Expression

Table 4.7-1 list the maximum length and allowed characters for the names for
Variables, Arrays, Constants, etc.

TABLE 4.7-1. Rules for Names

Name for

Maximum Length (number of
characters)

Allowed characters

Variable or Array

16

Letters A-Z, upper or lower.

Constant

16

case, underscore “ _” , and

Alias

16

numbers 0-9. The name must

Data Table Name

8

start with a letter. CRBasic is

Field name

16

not case sensitive

4.7.1 Expressions in Parameters

Many parameters allow the entry of expressions. If an expression is a
comparison, it will return -1 if the comparison is true and 0 if it is false
(Section 4.5.3). An example of the use of this is in the DataTable instruction
where the trigger condition can be entered as an expression. Suppose the
variable TC(1) is a thermocouple temperature:

DataTable(Name, TrigVar, Size)

DataTable(Temp, TC(1)>100, 5000)

Entering the trigger as the expression, TC(1)>100, will cause the trigger to be
true and data to be stored whenever the temperature TC(1) is greater than 100.

4.7.2 Arrays of Multipliers Offsets for Sensor Calibration

If variable arrays are used as the multiplier and offset parameters in
measurements that use repetitions, the instruction will automatically step
through the multiplier and offset arrays as it steps through the channels. This
allows a single measurement instruction to measure a series of individually

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