ICS PCI-WDT 500, Руководство по эксплуатации продукта

Страница: 29 / 44

Manual Number: 00650-144-1 Page 20
PCI-WDT 500/501 Manual
end;
writeln;
writeln(‘Waiting for timeout . . .’);
repeat
read_back := port[4]; { load control value }
until ((keypressed) OR ((read_back AND 128) = 0)); { check for bit 0 }
writeln;
writeln(‘Watchdog timed out successfully.’);
END.
VisualBASIC Utility Driver
Extensions to the VisualBASIC language are included on the diskette provided with your card. The
extensions are in a directory named VBACCES. These extensions are in the form of a .DLL, a
.GBL, and a VisualBASIC sample. Together these files allow you to access the port and main
memory space in a fashion similar to BASIC, QuickBASIC, Pascal, C/C
++
, Assembly, and most
other standard languages.
To use these files in a VisualBASIC program, you must create a .MAK file (File l New Project)
similar to the sample provided (or else, modify your existing project file) and include the .GBL file
(File | Add File). Once this has been done, VisualBASIC will be enhanced with the addition of the
following functions.
InPortb
Function: Reads a byte from a hardware port. Due to limitations of VisualBASIC, the
number is returned in an integer.
Declaration:
function InPortb(byval address as integer)as integer
InPort
Function: Reads an integer from a hardware port. This function returns the 16-bit
value obtained from reading the low byte from address and the high byte
from 1 .
Declaration:
function InPort(byval address as integer) as
integer
OutPortb
Function: Writes the lower eight bits of value to the hardware port at address. This
function returns the value output.
Declaration:
function OutPortb(byval
address as integer, byval
value as integer) as integer
OutPort
Function: Writes all 16 bits of value to the hardware port at address . This function