Rulbus Interface
[Implementation]

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Detailed Description

The Rulbus Device Class Library supports two Rulbus Interface cards:

• ISA Rulbus Interface card
• EPP Rulbus Interface card

The Rulbus interface class provides the means to read and write to the Rulbus that is connected to the specific Rulbus Interface card.

The proper interface class to use is created by the RulbusInterfaceFactory, based on the presence and contents of the Rulbus environment variable.

The responsibility to create the interface class is with class RulbusDevice. You can either request class RulbusDevice to create the Rulbus interface class, or let it create the Rulbus interface class automatically the first time a Rulbus device accesses the Rulbus.

Access to I/O-Ports

The Rulbus Interfaces are accessed via the computer's input/output ports. Windows NT type operating systems require that you have the privilege to access these ports. To give you that right, we use function AddMultiPort() of CanIO [CANIO] to open the address range required for the Rulbus Interface used.

See [DRIVERLINX] and [UNIIO] for other products that can provide access to input/output ports.

Modules
CanIO I/O-port access
	provide access to computer's i/o-ports.
Classes
class	EppRulbusInterface
	EPP Rulbus Interface. More...
class	IsaRulbusInterface
	ISA Rulbus Interface. More...
class	RulbusInterfaceFactory
	the Rulbus Interface Abstract Factory(87) Singleton(127). More...
class	TheRulbusInterface
	Rulbus Interface abstract base class. More...
Defines
#define	SPORTIO   "CanIO"
	string representation for PORTIO used.
Functions
short	Rulbus::inp (unsigned short port)
	read a byte from an input-output port
short	Rulbus::outp (unsigned short port, unsigned char value)
	write a byte to an input-output port.
bool	Rulbus::openIO (long base, int len)
	open port input-output address range on Windows NT type operating systems using CanIO. CanIO consists of canio.dll and canio.sys. openIO() first dynamically loads canio.dll and then calls AddMultiPort() to provide access to the requested input-output range.

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Function Documentation

short inp (  unsigned short  port  )

read a byte from an input-output port short inp(unsigned short port) { asm mov dx, port asm in al, dx asm xor ah, ah return _AX; } Parameters: port  portnumber Returns: byte read

short outp (  unsigned short  port, unsigned char  value )

write a byte to an input-output port. short outp(unsigned short port, unsigned char value) { asm mov dx, port asm mov al, value asm out dx, al asm xor ah, ah return (_AX); } Parameters: port  portnumber value  byte to write Returns: value

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