Multi-drop network

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I'm looking for a networking technology with the following requirements


1. Multidrop.No hub/router/switch
2. Up to 20 nodes
3. Transfer rate > 3MBytes/s
5. Supported by an off-the-shelf PC104 type card for an industrial PC
(master)
5. Easy to implement in HW (slave)


Anyone got any ideas? CANBus comes close, but isn't fast enough.

Cheers
TW


Re: Multi-drop network
A possibility is SPI (Serial Peripiheral interface).

Your PC104 will need a separate line for each device select (addressing
done in hardware, not part of the data protocol). It's a snap to
implement in hardware.

Cheers

PeteS


Re: Multi-drop network
Forgot to mention that it should have a range of around 5 metres.

TW


Re: Multi-drop network
Hello

Altera is looking for Sr. Applications Engr.  Please see link below.
If you know of anyone who would be interested, please have them email
their resume to me at snipped-for-privacy@altera.com.

http://www.altera.com/corporate/jobs/job_search.jsp?category=Applications%20Engineering

Thank you,
Rosie


Re: Multi-drop network

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http://www.altera.com/corporate/jobs/job_search.jsp?category=Applications%20Engineering

And this has what, exactly, to do with multi-drop networks?

--
Grant Edwards                   grante             Yow!  You should all JUMP
                                  at               UP AND DOWN for TWO HOURS
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Re: Multi-drop network
"Grant Edwards" ...
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Well, the message was dropped in this networked group 3 times...

Arie de Muynck



Re: Multi-drop network
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So you are looking for > 30 Mbits/s net. It means
a wavelength of less than 10 meters for the bit rate
(in practical cables less than 7 meters).

The only PC network technologies coming close
to the speed are 100 Mbit/s Ethernet and Firewire,
but both need hubs.

IMHO, the speed requirement makes it pretty difficult
to create a multi-drop network with the requested
cable lengths.

--

Tauno Voipio
tauno voipio (at) iki fi

Re: Multi-drop network

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You might be able to do it with a high speed card capable of SDLC.
This is a token passing protocol, and your devices need to be
connected in a ring. Infineon and others have devices that can handle
this protocol. AFAICR they should be able to handle the data rate.

Regards
  Anton Erasmus


Re: Multi-drop network
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How about 10base2 Ethernet?

There seem to be plenty of PC104 cards available.

  http://www.dpie.com/pc104/pia3610.html
  http://pc104.winsystems.com/products/pc104/pcmne2000bnc.html
  http://www.ampltd.com/prod/azlan.html

--
Grant Edwards                   grante             Yow!  My face is new, my
                                  at               license is expired, and I'm
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Re: Multi-drop network
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Dosen't cut it.

Re: Multi-drop network
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Doh. I misread the OP's requirement as 3Mbits/s.

--
Grant Edwards                   grante             Yow!  QUIET!! I'm being
                                  at               CREATIVE!! Is it GREAT
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Re: Multi-drop network
Hello,

Altera is looking for Sr. Applications Engr.  Please see link below.
If you know of anyone who would be interested, please have them email
their resume to me at snipped-for-privacy@altera.com.

http://www.altera.com/corporate/jobs/job_search.jsp?category=Applications%20Engineering

Thank you,
Rosie


Re: Multi-drop network
On Monday, in article

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Considering ISA is classed as a 2MBytes/sec bus (as PC104 = ISA), how are
you going to get 3MBytes/sec across?

Personally at these rates either use as someone else has said PC104plus for
higher bandwidth.

Then consider 100baseT network and accept the uncertainty factor, or split
your 20 nodes into sub-networks of smaller sizes each with its own 'network'
interface. Your network interface then can be RS422/485, or other means.

Personally I think you are trying to "fit a quart into a pint pot".

--
Paul Carpenter          | snipped-for-privacy@pcserviceselectronics.co.uk
<http://www.pcserviceselectronics.co.uk/ PC Services
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Re: Multi-drop network


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No problem.


Its not a real time issue, its a "20 port switches for industrial
temperature ranges cost serious money" issue.

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I'm designing down to a price. If it can't be done I'll have to think
again.

TW


Re: Multi-drop network
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And developing your own interface from scratch isn't?

Meindert



Re: Multi-drop network


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I've got no interest at all in developing an interface from
scratch.Thats why I'm asking here.
Although if it meant saving the cost of a 20 port Ethernet switch in
each machine I'd give it serious consideration.

TW


Re: Multi-drop network

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I recently got a 16port 10/100Mbit Switch at FRYs for 20$,
possibly not industrial temperature range.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

Re: Multi-drop network

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Grant

We are currently using 10Base 2. It is pretty much an obsolete
technology these days. Most of the major manufacturers have obsoleted
their PHYs for it. Designing it into a product that will have a life of
5+ years doesn't seem like a safe decision right now.

Cheers
TW


Re: Multi-drop network
Are you sure you want PC104 and not PC104+?  The PC104 with an ISA bus
is going to be a limitation. At least with PC104+ you get a PCI bus.

I've used some of Sealevel.com's PC104 equipment for RS422 on a 20+
node network.  They have a new product that supports 10M bps, but not
quite your 3Mbyte/sec.   ACB-104.ULTRA PC/104-Plus RS-232, RS-422,
RS-485, RS-530, RS-530A, V.35 Synchronous Serial Interface (uses
Z16C32)

    http://www.sealevel.com

If you can changed to PC104+ with a PCI interface instead of PC104
with an ISA bus, then General Standards.com might have a product that
gets close to what you want (only 10Mbits/sec..

The PC104P-SIO4B is a four channel full-duplex RS-422/485 serial
board. Each channel can operate up to 10Mbits/s. Up to 32 Kbytes of
FIFO buffering for both transmit and receive (256 Kbytes Total FIFOs)
data on each channel provides for a smooth and efficient interface
between the serial interfaces and the host computer. This product is
based on the Zilog Z16C30 high speed Integrated Universal Serial
Controller (USC) which supports Asynchronous, Isochronous, Bisync,
Monosync, HDLC, SDLC, External Sync and Nine-Bit protocols. The USC
chip provides full duplex operation with baud rate generators, digital
phase-locked loop for clock recovery and a full duplex DMA interface.
NOTE: some of the documentation for this product is still being
updated, so links below may be to documents with similar operation.

http://www.generalstandards.com/view-products.php?product=PC104P-SIO4B&formfactor=&function=Serial


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Re: Multi-drop network

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Yes. Its an absolute requrement that we be able to transfer 2MByte of
data in under a second.20%

TW


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