Hello dear all,
I have a problem with communication HP iPAQ hx 4700 with custom serial
(RS232) device via COM1. The custom device we're communicating with is made
by us and it has the following singularity: after receiving each byte via
serial port it pulses CTS line, so although CTS line still stays asserted
most of the time, it goes down for short period of time every time new byte
arrives to the device from the host. This is done in hardware long time ago
in order to signal to the transmitter, that recently sent byte has arrived
and this behaviour we can't change. This device works well with Windows 9x
and 2000 and with iPAQ COM6 via additional CF Card. Communication with PC
works both via COM1 and COM6.
Communication via COM1 with our device, however, works very slow and
unstable, no matter how we set up the port. We see via registry, that COM1
works through com16550.dll and COM6 through serial.dll, so implementation is
definetely different and this is probably explains it, but doesn't help to
solve.
We think, that the problem relies in some interrupt or similar event, that
occurs every time when CTS line toggles, but we don't know a way to
neutralize it, probably it's hardcoded (?).
Our question are:
do you know about any patches, that correct above effect?
how can we make serial communication work via different dll (changing
registry value + reboot makes communication unusable)?
maybe there are some settings to the communication port, that change this
behaviour?
Thank you,
Leonid Taouz
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System:
hx 4700
Windows Mobile 2003 SE Ver. 4.21.1088 (Build 14132)