i will try to develop the rfc2217 in udp
all data send via udp is sent to serial, but character 0xff allow change of
baud rate and others thinks like rfc2217 tells
this could work?
2011/11/29 Roberto Spadim <[email protected]>
> uhmmmm nice...
> well we could develop the protocol without changing baud rate?
> the reset is need for what? power up? search bus?
> could we change tcp to udp? it´s easier to implement in microcontroller
>
>
> 2011/11/29 Ziggy <[email protected]>
>
>> 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
>>
>>
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>
>
> --
> Roberto Spadim
> Spadim Technology / SPAEmpresarial
>
--
Roberto Spadim
Spadim Technology / SPAEmpresarial
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