Campbell Scientific CR1000KD CR800 and CR850 Measurement and Control Systems - Page 124

Section 7. Installation Table 11. Predefined Constants and Reserved Words mv50cR mv500c mv7_5 mvX10500 mv50R NSEC SCAN mvX1500 Select SUB sec TABLE TypeB SUBSCAN TypeJ TypeN TypeE TypeS UINT2 TypeR usec v2 Until v2c v60 v20 EX1 VX2 VX1 vX105 EX3 VX3 VX4 mv7_5c PROG STRING TRUE TypeK TypeT v10 v50 vX15 EX2 While 7.7.3.4.3 Alias and Unit Declarations A variable can be assigned a second name, or alias, by which it can be called throughout the program. Aliasing is particularly useful when using arrays. Arrays are powerful tools for complex programming, but they place near identical names on multiple variables. Aliasing allows the power of the array to be used with the clarity of unique names. The original name can be used interchangeably with the alias name as a Public or Dim variable in the body of the program. However, once the value is stored into a final storage table, the field name that is system created for the table (derived from the alias) must be used when accessing final storage data. Variables in one, two, and three dimensional arrays can be assigned units. Units are not used elsewhere in programming, but add meaning to resultant data table headers. If different units are to be used with each element of an array, first assign aliases to the array elements and then assign units to each alias. For example: Alias var_array(1) = solar_radiation Alias var_array(2) = quanta Units solar_radiation = Wm-2 Units variable2 = moles_m-2_s-1 One use of Alias and Units declarations is to reference a declared string constant as an aid to foreign language support. CRBasic example Foreign Language Support (p. 125) shows the use of Alias and Units declarations in building words comprised of non-English characters (see table ASCII / ANSI Equivalents (p. 202) ). 124