[argyllcms] Re: Calibrating the DTP94

Hi all,

> > The bit rate of 390 bits/s (i.e. 1 / 2.56ms) is rather unusual, and the
> > framing (3 start bits low followed by one start bit high in front of the
> > data) is rather unusual too.
> 
> You got me :(
> 
> > I'm not sure, whether the UART of a PC's
> > RS232 interface can be programmed to handle these frames directly (the
> > frames could be basically treated as if they were standard async frames
> > wih 1 start bit, 11 data bits, no parity and 2 stop bits, if the upper

Had a quick look at the manual - seems to a synchronous serial link.
A UART will in all probability not be able to handle this, the
date rate might not even be guaranteed (which isn't necessary on a
synchronous bus). However, since the data-rate is quite low, it should
be possible to use the RS-232 handshake and status signals for
clock-monitoring and bit-wise data transfer.
Also, you will need some pull-up resistors and maybe a level-translator
(MAX232 like) for the physical interface to a PC's serial port (depending
on the voltage levels of Busy, SCK and Measurement Request).
It's a bit stange that the data output is open-collector, but SCK
and Busy don't seem to be.


Regards,

Oliver

Other related posts: