Vaisala PTB210 SERIES Manuel d'instructions télécharger pdf (Page 37)

4.3 Declarations

The declarations at the beginning of an CRBASIC program are like an abstract for

the user to know about the parameters of capital importance. This enfoldes the sen-

sors with their port-usage at the data logger, peripheral devices, both measurement

and data storge characteristics. However, this program segment has nothing to do

with the actual program run and just gives an account of readings and terms.

4.3.1 Variables and Arrays

A variable is a packet of memory, given an alphanumeric name, through which

measurements and processing results pass during the program execution. Variables

are declared either as PUBLIC, ALIAS or DIM at the discretion of the programmer.

PUBLIC and ALIAS variables can be viewed through the CR1000KD or software

numeric monitors. DIM variables cannot but are not to be used for programming

the instrumentation of the weather station. The amount of variables depends on

the number of sensors and calculation processes which are to be done. First of all,

every sensor gets his own variable. If there are any calculations in the runtime of

the main scan, this result has to be assigned to annother variable. For example the

variables for the counter of measured data per interval are expressed as following:

Public N

Public Count

When a variable is declared, several variables of the same root name can also be

declared. This is done by adding a suﬃx of "(x)" to the alphanumeric name, wich

creates an array of x number of variables that diﬀer only by the incrementing number

in the suﬃx. For example, rather than declaring some similar variables as follows,

Public T107_C_1

Public T107_C_2

Public TRHData_1

Public TRHData_2

Alias TRHData_1=TempC

Alias TRHData_2=HumidC

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Vaisala PTB210 SERIES Manuel d'instructions Page 37