rs-485 info / tutorial / drivers needed

[pharos]

avrco pascal 1wire

Hello All,
I need some good tutorial/notes for RS-485 and any s/w drivers for that. Please help.

Enjoy,

pharos

 

[tom324]

485info

RS-485 is "electrical level" interface. It is half duplex. I assume you are interested in some specific protocol that uses RS485 as interface?

Tom

 

[gabby]

Hi
You have same companny that make that drivers here some link to the
interface chips datasheet:

1. sipex.
**broken link removed**

2. linear.
https://www.linear.com/prod/pft.html?product_family=interface

3. national semiconductors.
**broken link removed**

4. maxim/dallas.
**broken link removed**


Best regards. 8)

 

[pharos]

Hello Tom,
I may be wrong, but what i think is that RS-485 is a serial protocol and i need to develop some s/w drivers over that.

Thanks,

pharos

 

[tom324]

I may be wrong, but what i think is that RS-485 is a serial protocol and i need to develop some s/w drivers over that.

No, RS485 is not a 'protocol'. Protocol is a set of rules which determine how a connection is established, maintained and terminated. Data exchange is also part of these rules. Protocols are usually implemented by software layer.

Tom

 

[ljmnunes]

hello, pharos.

As tom324 said, RS485 is a hardware interface not a protocol. Some people call it "protocol RS485" but it is not right.

There are a lot of protocol specification in the net. You can only choice that you need.

Can I help you? I used Modbus protocol for years.

 

[TheHungry]

Shematics and other **broken link removed**

 

[stroma]

Hi Pharos,
Tom324 is right about RS485 - it is just interface, not a protocol. You probable have to decide which protocol you will implement in software driver(s). I’m using Dallas “1-wire” protocol over RS485 interface to increase distance of the net.
Regards,
stroma

 

[pharos]

Hello guys,
Thanks for the information. Please give me some useful links for RS-485 tutorials. I basically want to implement a serial protocol over RS-485.

regards,

pharos

 

[ted]

It all depends what is your application. For instance, for instrumentation using serial links (RS232, RS485 +others) you may get ready made software for free at
https://www.windmill.co.uk/rs232.html

You may also find intersting to read
https://www.ece.utexas.edu/~valvano/manual/Lab10.pdf (See also the directory .../manual/ for more documents)
The same professor, Jonathan W. Valvano, has also a software archive (written in C for MC68HC812) containing different things, including a driver for RS-485 networking:
https://www.ece.utexas.edu/~valvano/programs/

Good luck,
Ted

 

[ghbolivar]

hey! have you already implemented your protocol?
Anyway, i recomend you to take a look at **broken link removed**
They have created SNAP, a very good protocol. It is open an free

 

[jarmestor]

For RS-485 cabling guidelines, you can view the technical note **broken link removed**

jarmestor

PD:
I think that RS-485 is an electrical specification in many physical layer protocols (bitbus, profibus,....)

 

[7rots51]

hello

you can use modbus protocol for rs485 interface.
https://www.modicon.com
https://www.modbus.org

you can find c source code on modbus in elektroda.

you can goto https://www.advantech.com and check their ADAM series ASCII command response protocol,it is very simple but efficient.

 

[mdamdam]

E-Lab have a 9bit network protocol for AVR µC possible but tricky to interface with PC

 

[avra]

If you want protocol I use written in E-L-a-b A-V-R-c-o P-A-S-C-A-L, say it. I can also give you windows test software for this protocol.

Avra

 

[Trishool]

RS485 is a standard !!

Hello guys,
Thanks for the information. Please give me some useful links for RS-485 tutorials. I basically want to implement a serial protocol over RS-485.

regards,

pharos

pharos ,

RS485 is a standard , see RS485.com there yo'll find plenty of resource .

Ts

 

[dsp2x]

STOR /RS422 and RS485 Application Note.pdf
550 RS422 and RS485 Application Note.pdf: Cannot create file.
RS422 and RS485 Application Note.pdf: Cannot create file
Failed [RS422 and RS485 Application Note.pdf: Cannot create file]

 

[huahua]

**broken link removed**

Hope it helps

 

[zohar]

S.N.A.P Protocol

Hi,
We build an 485 Controller network, after reviewing some major leading industry protocols (such as CAN, TCP, PPP etc.), we found the SNAP as the perfect protocol to controller network. It is a very flexible protocol that can meet ALL MCU application needs from the very smaller resources and up to 16 bits controller end so no.
If you need any help, PM me.

yours,
Zohar