Multi-drop network

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

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

Forgot to mention that it should have a range of around 5 metres.

TW

Ted wrote:
> 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
> 4. Supported by an off-the-shelf PC104 type card for an industrial PC
> (master)
> 5. Easy to implement in HW (slave)

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

Ted wrote:

> 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.
> 
Don't like to offend, but did you make your calculations on the best use of
CAN? I mean CAN should not be used for large data junks and repeating
transmission. If used in the suggested event driven communication mode,
sending data only if information changes, it saves a lot of bandwith.

Regards
  Heinz
-- 

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On 7 Nov 2005 02:57:21 -0800, "Ted" <ted.wood@sortex.com> wrote:

>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.
>

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

On 2005-11-07, Ted <ted.wood@sortex.com> wrote:
> 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)

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
                               visi.com            under a doctor's care!!!!

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


On 7 Nov 2005 02:57:21 -0800, "Ted" <ted.wood@sortex.com> wrote:
>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
>

Grant Edwards wrote:
>>3. Transfer rate > 3MBytes/s = 30Mbits/S
> How about 10base2 Ethernet?  = 1Mbytes/S

Dosen't cut it.

On 2005-11-08, Donald <donald@dontdoithere.com> wrote:
> Grant Edwards wrote:
>>>3. Transfer rate > 3MBytes/s = 30Mbits/S
>> How about 10base2 Ethernet?  = 1Mbytes/S
>
> Dosen't cut it.

Doh. I misread the OP's requirement as 3Mbits/s.

-- 
Grant Edwards                   grante             Yow!  QUIET!! I'm being
                                  at               CREATIVE!! Is it GREAT
                               visi.com            yet? It's s'posed to SMOKEY
                                                   THE BEAR...