Problem with PCI serial communication card in Pentium 4, 2.6

We have a strange problem.
The system running under QNX 4.25 RTOS in PC H/W platform. The

application software connects to a number of devices (card
readers)
through RS 422 port. The transmission is at 9600 baud. The system
runs
perfectly with old PC (up to Pentium 3 PC). When the same
application
software is run in Pentium 4 based PC (2.6GHz - 3 GHz), it is
observed
that for lower system clock (2.6 GHz) the application software
communicates to serial card readers without any problem.

When connected in Petium 4 PC (3 GHz) with higher PCI clock, it
is
observed that application software terminates after indicating
‘’’‘Memory Fault’’’’ (SIGSEGV), at memory xxxx:xxxx.
It is observed that
if we remove the Ethernet Networking card from PCI slot 1 and
place
the
CP-132 in that slot and donot put the Ethernet card, the system
donot
give any memory fault. However, it does not carry out any serial

communication function (both transmission and reception).

It is to be mentioned here, for lower speed PC, the serial card
is not
slot dependant, whereas for higher speed PC, the serial card work
only
in specific slot (slot 1). The size of RAM in lower speed PC is
also
less (256MB). It is found from BIOS setup that 2.66GHz PC is
having
DRAM frequency of 100MHz whereas for 3 GHz PC, the system
frequency is
800MHz and System Memory speed is 266 MHz.

Can anybody give some clue to this problem? How to solve this problem?

Thanks in advance.

R kumar

Just a wild guess here, but you might want to check your PIV bios and
see if the CP-132 and Ethernet are sharing an interrupt. This is
supposed to work, but it could be the problem.

ranajitkwrote:
We have a strange problem.
The system running under QNX 4.25 RTOS in PC H/W platform. The
application software connects to a number of devices (card
readers)
through RS 422 port. The transmission is at 9600 baud. The
system runs
perfectly with old PC (up to Pentium 3 PC). When the same
application
software is run in Pentium 4 based PC (2.6GHz - 3 GHz), it is
observed
that for lower system clock (2.6 GHz) the application software

communicates to serial card readers without any problem.

When connected in Petium 4 PC (3 GHz) with higher PCI clock, it
is
observed that application software terminates after indicating

‘’’‘Memory Fault’’’’ (SIGSEGV), at memory xxxx:xxxx.
It is observed that
if we remove the Ethernet Networking card from PCI slot 1 and
place
the
CP-132 in that slot and donot put the Ethernet card, the system
donot
give any memory fault. However, it does not carry out any
serial
communication function (both transmission and reception).

It is to be mentioned here, for lower speed PC, the serial card
is not
slot dependant, whereas for higher speed PC, the serial card
work only
in specific slot (slot 1). The size of RAM in lower speed PC is
also
less (256MB). It is found from BIOS setup that 2.66GHz PC is
having
DRAM frequency of 100MHz whereas for 3 GHz PC, the system
frequency is
800MHz and System Memory speed is 266 MHz.

Can anybody give some clue to this problem? How to solve this
problem?
Thanks in advance.

— update: In Pentium 4, 3 GHz machines, the PCI card work when
put in one specific slot (in one m/c slot 3), the application program

does not terminate with Memory fault (mentioned above) - but does not
carry out any communication. In other slots, the application program
terminates indicating Memory Fault. There is no other card present in
the system.

Thanks in advance.

Ranajit Kumar


R kumar

This really sounds like a problem with your 3Ghz P4, not the software.