[Wine] Win app under wine that use RS-485

[Martin Gregorie]

On Wed, 2011-03-09 at 12:04 -0700, James McKenzie wrote:
> On Wed, Mar 9, 2011 at 11:24 AM, aleroot <wineforum-user at winehq.org> wrote:
> > No, in /dev/ttyS i have only the 4 serial port (rs-232) on the machine ?
> >
> > Should Linux allocate /dev/ttySX for RS-485 ? What device name under /dev should i have ?
> >
> It should.  It should by the next ttyS device (ttyS4 if my memory serves me.)
> Are you using a special board/device for RS-485 communications?  Does
> this device have a Linux driver?  Wine cannot run Windows drivers
> because how and where drivers are loaded in the operating system
> architecture.
> 
Disclaimer. I've never used RS-485 but some quick research shows the
following:

- RS-485 is a way of linking a number of devices on a multi-drop cable,
  so the driver must explicitly switch the transmit side of each node
  on and off. Devices are referred to as nodes.

- RS-485 is a master/slave setup with the master node controlling
  the other (slave) nodes and controlling which node can transmit.

- RS-485 can be full or half duplex. This is a physical choice:
  half-duplex uses a single twisted pair while full duplex needs two
  twisted pairs.

- RS-485 can be, and often is, implemented with standard UARTs, e.g. 
  an 8250 or 16550. The hardware of some RS-232 serial port adapter
  cards is switchable to RS-485 with a jumper or you can use RS-485
  adapter cards.

- Linux *may* set up RS-485 ports as /dev/ttyS[0-9]. What it does would
  depend on whether the kernel checks whether a serial port is S-232 or
  RS-485: I don't know what it does. 

- there is no such thing as an RS-485 transmission protocol. RS-485
  only defines the physical link layer.
 
- each node on a multi-drop line has a unique address and any node can
  send data to any other combination of nodes once the master has given
  it permission to send.

- Linux RS-485 drivers are available. 

Your distro and/or the people who implemented the communication protocol
your app is using should know what adapter cards and drivers are
available, so ask them.


Martin