Do you still use "RS232" or something else?

Hi Oliver

I have embedded my comments.

On 14 Jan., 13:13, Oliver Betz <ob...@despammed.com> wrote:
> Hello All,
>
> although most of our (industrial) clients still use to have computers
> with a "real" serial port, I observe a small but increasing number
> struggling with bad USB adapters and asking for other interfaces.
>
> Therefore I'm reconsidering the best suited interface for device
> configuration and diagnosis.
>
> Do you still use EIA-232? Customers complaining?

Unfortunately - yes.

>
> What do you consider a suitable "successor"?

Low-power ethernet supporting IEEE 802.3az (optionally with IEEE
802.3af/at support)

>
> * USB. Can be even cheaper than EIA-232, and AFAIK a HID doesn't
> require administrator rights for "installation". But we have to supply
> software to the user (cost, distribution) and there remain some traces
> on the host system.

Get the "best" of both worlds - EIA-232 (and RS485 ! ) over USB -
using FTDI chips e.g. FT232RL.

Has free drivers for the main platforms:
http://www.ftdichip.com/

Dump "null-modem", 25-pin, 9-pin, 8P8C and 10P10C for EIA-232.

Awkward speed selection and handshaking options (use nothing, xon,
xoff og hardware? The different wiring schemes combined with - that
e.g. Nortel, HP, Cisco, UPS, Trapeze and Juniper have their own wiring
and different plugs!

EIA-232 autonegotiation sucks and does NOT negotiate handshaking
features and other (missing, damaged or present) hardware signal wires
- and is even asymmetrical (RTS, CTS) ! - it all eats your time and
patience.

EIA-232 transport is only byte oriented - not packet oriented; so it
is inefficient when evaluated with todays needs.

EIA-232 is unbalanced and therefore has very low common-mode
suppression. The different signals interfere with each other, if the
cable is longer than approx. 5 meters.

>
> * Ethernet, TCP/IP, HTTP, DHCP or Zeroconf? Every recent computer has
> Ethernet and a web browser, so the user needs no additinal components
> besides a patch cord. But if he wants to be connected to a(nother)
> network, there might arise problems. And the cost of Ethernet
> connectivity is higher than EIA-232 or USB.
>
> More alternatives?

IrDA?
http://en.wikipedia.org/wiki/Infrared_Data_Association
Quote: "...Transmission rates fall into various categories: SIR, MIR,
FIR, VFIR, UFIR, and Giga-IR...."

>
> Oliver
> --
> Oliver Betz, Munich
> despammed.com is broken, use Reply-To:

On 14 Jan., 13:13, Oliver Betz <ob...@despammed.com> wrote:
> Hello All,
...
> * Ethernet, TCP/IP, HTTP, DHCP or Zeroconf? Every recent computer has
> Ethernet and a web browser, so the user needs no additinal components
> besides a patch cord. But if he wants to be connected to a(nother)
> network, there might arise problems. And the cost of Ethernet
> connectivity is higher than EIA-232 or USB.
...

http://en.wikipedia.org/wiki/Energy_Efficient_Ethernet

combine it with a DHCP-server and client.

If the client can not find an existing DHCP-server - your hardware
starts it own (but shut it down if another DHCP-server is detected).
Then a mgmt pc will eventually get a ip-configuration.

On 14 Jan., 21:44, Glenn <glenn2...@gmail.com> wrote:
> On 14 Jan., 13:13, Oliver Betz <ob...@despammed.com> wrote:> Hello All,
> ...
> > * Ethernet, TCP/IP, HTTP, DHCP or Zeroconf? Every recent computer has
> > Ethernet and a web browser, so the user needs no additinal components
> > besides a patch cord. But if he wants to be connected to a(nother)
> > network, there might arise problems. And the cost of Ethernet
> > connectivity is higher than EIA-232 or USB.
>
> ...
>
> http://en.wikipedia.org/wiki/Energy_Efficient_Ethernet
>
> combine it with a DHCP-server and client.
>
> If the client can not find an existing DHCP-server - your hardware
> starts it own (but shut it down if another DHCP-server is detected).
> Then a mgmt pc will eventually get a ip-configuration.

Ethernet must have:
http://en.wikipedia.org/wiki/Autonegotiation

so an awkward crossover cable is not needed.

On Jan 15, 1:13=A0am, Oliver Betz <ob...@despammed.com> wrote:
>
> Do you still use EIA-232? Customers complaining?



> What do you consider a suitable "successor"?
>
> * USB. Can be even cheaper than EIA-232, and AFAIK a HID doesn't
> require administrator rights for "installation". But we have to supply
> software to the user (cost, distribution) and there remain some traces
> on the host system.

I noticed this
http://www.embeddedtechnology.com/article.mvc/Silicon-Labs-Bridge-IC-Family=
-Simplifies-0001

I've not used these, but they claim

["'The new CP2110 and CP2112 bridge ICs comply with the USB-HID class
specification natively supported by most operating systems, thus
removing the need to install drivers. This eliminates the risk of
incompatible and exhaustive driver updates and obviates the need for
customers to provide companion CDs with specialized driver information
or to maintain download sites for driver updates"]

Is that enough for ("device configuration and diagnosis"). ?
[I see they side-step mention of ones software..]

I also see the new NCT6681D from Nuvoton, (128 pins seems std size)

["NCT6681D is the first IC of Nuvoton`s new product line, or eSIO,
which combines a built-in microcontroller and traditional legacy SIO
functions. NCT6681D supports a rich set of features and targets the
All-in-One PC applications, high-end motherboard applications that
need the built-in microcontroller to fulfill the customized features,
and any other applications that microcontroller can better execute the
performance."]

includes this

["LPC interface, Printer Port, 2 Serial UARTS and KBC "]

So it looks like RS232 is not a complete dead duck just yet ?.

Of course, a vendor has to decide to use this device, and to fit RS232
connectors/level shifters and the latter is most likely the stumbling
block....

-jg

On 14 Jan., 21:44, Glenn <glenn2...@gmail.com> wrote:
> On 14 Jan., 13:13, Oliver Betz <ob...@despammed.com> wrote:> Hello All,
> ...
> > * Ethernet, TCP/IP, HTTP, DHCP or Zeroconf? Every recent computer has
> > Ethernet and a web browser, so the user needs no additinal components
> > besides a patch cord. But if he wants to be connected to a(nother)
> > network, there might arise problems. And the cost of Ethernet
> > connectivity is higher than EIA-232 or USB.
>
> ...
>
> http://en.wikipedia.org/wiki/Energy_Efficient_Ethernet
>
> combine it with a DHCP-server and client.
>
> If the client can not find an existing DHCP-server - your hardware
> starts it own (but shut it down if another DHCP-server is detected).
> Then a mgmt pc will eventually get a ip-configuration.

Maybe combine ethernet with LVDS-like signaling:
http://en.wikipedia.org/wiki/LVDS
Quote: "...For example, the static power dissipation in the LVDS load
resistor is 1.2 mW, compared to the 90 mW dissipated by the load
resistor for an RS-422 signal...."

On 14 Jan., 21:44, Glenn <glenn2...@gmail.com> wrote:
> On 14 Jan., 13:13, Oliver Betz <ob...@despammed.com> wrote:> Hello All,
> ...
> > * Ethernet, TCP/IP, HTTP, DHCP or Zeroconf? Every recent computer has
> > Ethernet and a web browser, so the user needs no additinal components
> > besides a patch cord. But if he wants to be connected to a(nother)
> > network, there might arise problems. And the cost of Ethernet
> > connectivity is higher than EIA-232 or USB.
>
> ...
>
> http://en.wikipedia.org/wiki/Energy_Efficient_Ethernet
>
> combine it with a DHCP-server and client.
>
> If the client can not find an existing DHCP-server - your hardware
> starts it own (but shut it down if another DHCP-server is detected).
> Then a mgmt pc will eventually get a ip-configuration.


October 08, 2008 Gigabit PHY IC Complies With Energy-Efficient
Ethernet Guidelines
http://electronicdesign.com/article/communications/gigabit-phy-ic-complies-with-energy-efficient-ethe.aspx
PEF-7071
http://embeddedsystemnews.com/infineon-announces-xway-phy11g-the-first-gigabit-ethernet-phy-ic-with-eee-guidelines-for-energy-efficiency.html
Quote: "...
XWAY-PHY11G is the first IC on the market to implement the Energy
Efficient Ethernet (EEE) guidelines, which are based on the upcoming
IEEE 802.3az standard. The Infineon PHY reduces its energy use by up
to 90 percent (50 mW instead of 500 mW) during periods of idle
..."

Supplement:

Thanks for all replies.

Since several people voted for USB - UART adapters, usually FTDI FT232
flavour: That's also my preferred solution for people not being
long-sighted enough to by a suitable computer with a real comm port.

But I suggest this only as a solution separate from my device (not
integrated), because the installation requires Administrator rights,
IOW is much more intrusive than I want one of my designs to be.

Oliver
-- 
Oliver Betz, Muenchen (oliverbetz.de)

-jg wrote:

>I noticed this
>http://www.embeddedtechnology.com/article.mvc/Silicon-Labs-Bridge-IC-Family-Simplifies-0001
>
>I've not used these, but they claim
>
>["'The new CP2110 and CP2112 bridge ICs comply with the USB-HID class

HID is the way I would go if I wanted to offer USB, because it doesn't
need driver installation.

And the Silabs is a simple option / alternative to EIA-232. Cost is
similar to an EIA-232 driver.

Depending on production volume, it can be cheaper to use a
microcontroller with USB and own HID stack.

But although I didn't need to bother the customer with driver
installation, I had to supply host software for every operating system
my customers use. Currently Win32 seems to be enough, but I had to be
prepared to offer the software for Linux and Mac.

With EIA-232, I can tell the customer to use the terminal software he
hates least, readily available on every system down to my HP48
calculator or an old Palm pilot.

> So it looks like RS232 is not a complete dead duck just yet ?.

I also think so. But I keep the USB HID in mind as an option.

Maybe someone even makes a "terminal program" for the CP2110 some day,
if not we had to do so.

Oliver
-- 
Oliver Betz, Muenchen (oliverbetz.de)

On 2011-01-14, Oliver Betz <obetz@despammed.com> wrote:
>
> although most of our (industrial) clients still use to have computers
> with a "real" serial port, I observe a small but increasing number
> struggling with bad USB adapters and asking for other interfaces.
>
> Therefore I'm reconsidering the best suited interface for device
> configuration and diagnosis.

Others have made a fine job of considering the technical issues so
I'll restrict myself to the user perspective here. 

RS232 runs can be fairly long - 100m easily enough over regular
Cat5 cables.  USB is a complete non-starter over that kind of
distance meaning the equipment and computer need to be located
together.  That isn't always convenient.

RS232 with a CLI interface does not depend on anything special on
the host computer - just a terminal emulator.  That means I can
use any machine that comes to hand and I don't need to track down
and install software first.  If it's a twenty year old bit of kit
I am not dependant on the manufacturer still being in existence
and providing new software for a modern OS.  Of course a CLI needs
more space than something that simply downloads a new configuration
in a fixed binary format but that may be a matter of a kilobyte -
probably less than you need to implement USB or a TCP/IP stack
before you even think of your application-level processing.

RS232 is still ubiquitious in many applications and there are many
methods of handling it.  A simple use may be direct connection to
a PC but dial in use becomes a possibility for remote access, and
at the high end there are the consoles servers from Cyclades and
the like for those that have to manage dozens of devices in a
robust, organised manner.

As for the quality of USB-serial adapters, if you keep to a couple
of simple rules you shouldn't have any issues.  First of all, if
you use an RS232 port make sure you actually use RS232 - it is a
serial interface, not a GPIO port. (Ab)using handshaking pins to
do something they were not intended for is always going to be asking
for trouble.

The other potential gotcha is with break handling.  In my view it
is unforgivable that there are adapters that can't send a break
signal but they are out there - bear that in mind at the design
phase so you never need a break and it simply won't be an issue.

On a purely personal basis I'd much rather see an RS232 port that
I know I'm likely to never have issues with, rather than a USB
interface that depends on a vendor supplied app that may be useless
in five years time.  Network configuration is slightly better but
that depends on how the initial network config is done (IP address
and netmask).  A DHCP client depends on a network running DHCP in
the first place, and anything that initially sets itself up as DHCP
server (like most home routers) can't be connected to a production
network until they are configured.

-- 
Andrew Smallshaw
andrews@sdf.lonestar.org

-jg <jim.granville@gmail.com> wrote:


> ["'The new CP2110 and CP2112 bridge ICs comply with the USB-HID class
> specification natively supported by most operating systems, thus
> removing the need to install drivers. This eliminates the risk of
> incompatible and exhaustive driver updates and obviates the need for
> customers to provide companion CDs with specialized driver information
> or to maintain download sites for driver updates"]

ahh, that's seems good.
I'm using the CP2102 right now, but it's true that the need to install a
driver is quite annoying.
I'll check it out :)

Thanks Bye jack


-- 
Yoda of Borg am I! Assimilated shall you be! Futile resistance is, hmm?