Technical data

Linkage with PLC
CP 486 ⋅ 00/14 VIPA GmbH 107
programs can be started subsequently. This option is only meaningful, if communication ensues
exclusively via banks 0 and 1 (CP passive). By pressing the F10-key and subsequent confirmation
with "j" the driver will be removed again.
/?, /H or /hxx
This option shows a list of all possible options of the driver.
Attention:
The COM-driver is designed to work with CP486-modules of the VIPA GmbH exclusively and can
be installed on these systems solely. Loading the driver on different AT-systems, even on i386 or
i486 processor, causes an immediate system-hang-up.
Reserved interrupts:
The driver uses several software interrupts for operation and communication with the applications
software of theCP-module:
- INT 1Ch Timer-Interrupt and INT 28 DOS-Idle-Interrupt
The so called ticker-interrupt with number 1Ch, as well as the so called DOS-idle interrupt are used
for routine and cyclical check of the bank. By this, it is regularly checked, whether the PC tries to
synchronize the banks recently. After executing the CP-specific functions, the initial interrupt
service routine is called.
- INT 74h (IRQ 12):
The CP486 uses the hardware-IRQ 12, which occupies software-interrupt 74h. This interrupt will be
triggered, if BASP is active in PC, or if the highest memory location of every bank (byte1023) is
written by the PC. The usage of the interrupt permits fast reaction of the CP to a request by the PLC.
After processing the CP-specific functions the initial interrupt service routine is called. In this
manner, different devices can use IRQ 12.
- INT 78h Service-Interrupt:
This interrupt is to be used by applications software in the CP to call functions of the driver, for
example data exchange with the PC via banks 2 and 3. Different functions can be triggered by
corresponding assigment of the processor registers. If INT 78 is called with register values, which
are invalid for the CP486 communication, the initial interrupt service routine is called.