Rockwell-automation 2708-NBD VBASIC Language Development Kit Manual de usuario descargar pdf (Pagina 71)

Appendix C

Application Library Subroutines

C–3

The most important events are:

TimeoutEvent The input timer has expired. . . .

NetEvent Read from network has occurred. . . . . . . .

ComEvent Read from the main comm port. . . . . . .

AuxEvent Read from the aux comm port. . . . . . .

When ComEvent or AuxEvent has occurred, InCom$ contains the LINE

INPUT format line which was read from the comm line. When NetEvent has

occurred, InNet$ contains the record from the host. The events which you

want to test for are indicated by the “mask” parameter. Each device which

you want tested MUST have a bit set in the mask. Bits are set by building a

mask using the constants: KbdMask, TimeoutMask, BadgeMask, NetMask,

ComMask, AuxMask, and SensorMask.

To simplify matters, some special mask values are also allowed. These are:

0 = Read from keyboard only

1 = Read from keyboard with timeout (see ReadEvent%)

2 = Read from keyboard and SLOT, etc. with timeout

Note: Timeouts only apply to reads which wait for an event. TestEvent%

never waits. See ReadEvent% for more info.

e = TestEvent% ( mask% )

FUNCTION TestEvent% ( mask% )

SaveEvent Saves the previous event to allow it to happen again.

Saves the event which has just occurred from TestEvent%. The very next

TestEvent% will return this event code.

SaveEvent eventcode%

SUB SaveEvent ( e% )

ReadEvent% Waits for a low level event.

Waits for an event to occur. The event(s) to wait for are specified in the same

manner as TestEvent%.

For timeouts set the global variable TIMEOUT% to the number of 1/100

second intervals you want to wait before a TimeoutEvent is returned. The

value of TIMEOUT% is not modified by %.

e = % ( mask );

FUNCTION % ( mask% )

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Rockwell-automation 2708-NBD VBASIC Language Development Kit Manual de usuario Pagina 71