Iai-america XSEL-QX Manuel d'utilisateur télécharger pdf (Page 439)

100

101

415

Appendix

(4) Program

[1] String process commands

A “string” refers to a series of characters. This controller supports global strings and local strings.

Global strings can be read or written commonly from any program, while local strings are effective

only within a given program and cannot be used in other programs. Numbers in different ranges are

assigned to global strings and local strings, respectively:

Global areas 300 to 999 (700)

Local areas 1 to 229 (229)

String commands are needed because normally controllers communicate with external devices by

means of serial communication, and serial communication data must be processed as strings. This

controller supports serial communication. In operations performed via serial communication, strings

may have to be compared against each other, moved, or converted. This controller provides a set of

commands to do all these.

[2] Explanation of transmission format

Communication by this system is basically implemented through exchange of strings.

Rules about these strings are set beforehand, such has which strings are used in which operations,

so that the receiving side can recognize each string and perform a corresponding operation.

A combination of these strings, and characters indicating the end of a string, is called a

“Transmission Format.” The user can define desired transmission formats freely.

For example, let’s say a 4-character string “HOME” is defined as a command to perform home return.

This string is followed by a character indicating the end of a string. In theory, any character can be

used to serve this role. In reality, however, “CR” and “LF” must be used according to the definitions

used by the PC.

Example of transmission format

String indicating a home

return command

Character indicating

the end of a string

1 2 ... 434 435 436 437 438 439 440 441 442 443 444 ... 557 558

Commentaires sur ces manuels

Pas de commentaire

Iai-america XSEL-QX Manuel d'utilisateur Page 439

Commentaires sur ces manuels

Produits connexes et manuels pour Matériel Iai-america XSEL-QX