You really need to read the datasheet to understand the issues. But the biggest issue is that of resetting the DS2480 itself, not in the 1-wire commands/data.
You have basically two methods of resetting the chip: - power cycle the chip - reset it via software Hardware If the 2480 is power stealing from the serial port, you can close the port and reopen it, causing the control leads to toggle. This does a power cycle of the chip. Otherwise you need to somehow remove power from the chip and reapply it. Software The DS2480B will perform a master reset equivalent to the power-on reset if it detects start polarity in place of the stop bit. As described in the datasheet, you have a couple of methods of doing this: - send BREAK sequence - send character with SPACE parity A BREAK sequence is usually defined as 350ms or more of a continuous SPACE condition. Setting the port speed to 4800 and sending a NULL will cause SPACE condition for enough 9600 bps bit times that the 2480 resets. It's sort of a simulated BREAK. This is why some 1W drivers want to change the port speed. With no TCP you have no telnet, and without telnet protocol you have no IAC BRK, which is used by terminal/port servers to generate a BREAK signal on the serial port. You also have no RFC2217 so no way to change the port speed and use the 4800 bps NULL character method. It's only the sending a character with SPACE parity that may work over UDP. The final thing to remember is that the DS2480B powers up in 9600 bps mode. So the serial port on your UDP/serial converter must be set to 9600 bps. This is going to limit throughput but again, without TCP/telnet/RFC2217 you can't change the port speed in-band via software. I guess the summary is that DS2480B on a UDP/serial converter should work if the DS2480B device reset is accomplished by sending the character with SPACE parity. Havent tried it myself though. Ziggy On 11/29/2011 12:13 PM, Roberto Spadim wrote: > hi guys, someone could explain how ds2480b works? > for example, what it must do with serial port (change baud rates, > set/read DTS RTS etc.., send / receive) > most important commands > > not all datasheet just some important points > > -- > Roberto Spadim > Spadim Technology / SPAEmpresarial ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Owfs-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/owfs-developers
