External variables

Read/write accesses to channel-specific and global external variables V.E.* can be made from the realtime cycle.. The variable must be defined as synchronous for a write access.

Programming Example

Definition of a synchronised V.E. variable

...

var[0].name VALUE1

var[0].type REAL64

var[0].scope GLOBAL

var[0].synchronisation TRUE

var[0].access_rights READ_WRITE

...

Only synchronised variables may be written in realtime cycles.

With a read access to a V.E. variable, its value is dependent on its synchronisation.

A synchronised variable is evaluated in the realtime context of the CNC.
An asynchronised variable is evaluated at the time of decoding and is used as a constant.

Programming Example

Accesses to V.E. variables

; Pre-assign variables

V.E.SYNC = 47 ; synchronous variable

V.E.SYNC = 11 ; asynchronous variable

; Define realtime cycle

#RT CYCLE [SCOPE = PROG]

; Run through instructions only once

$IF ONCE 1 < 2

; Assign new value

V.E.SYNC = 99

; has the value 198

V.E.VALUE1 = 2 * V.E.SYNC

; V.E.ASYNC always has the value 11 in this realtime cycle

; right side has the value 22

V.E.VALUE2 = 2 * V.E.ASYNC

$ENDIF

#RT CYCLE END

; End main program

M30