Re: How connect PC Embedded to MDB (Vending Machine)

On 30 sep, 03:09, "PhilW" <p...@xxxxxxxxxxxxx> wrote:
<juanma.freela...@xxxxxxxxx> wrote in message

news:73aaa712-5e75-4674-a2b2-3a62b78569a3@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On 29 sep, 20:29, James Beck <j...@xxxxxxxxxxxxxxxxxxxxxxx> wrote:





In article <29c16500-d3a1-4d46-a7d4-
59492ef13...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>, juanma.freela...@xxxxxxxxx
says...

On 29 sep, 17:56, James Beck <j...@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
In article <3834d44e-355e-4d5f-af57-87e9ec4c0a97
@z72g2000hsb.googlegroups.com>, juanma.freela...@xxxxxxxxx says...

On 29 sep, 16:33, James Beck <j...@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
In article <1da3a443-e530-487a-8cb7-e4166e206414
@i76g2000hsf.googlegroups.com>, juanma.pal...@xxxxxxxxx says...

On 29 sep, 11:11, juanma.freela...@xxxxxxxxx wrote:
On 29 sep, 03:32, "PhilW" <p...@xxxxxxxxxxxxx> wrote:

<juanma.freela...@xxxxxxxxx> wrote in message

news:c4d5b1b0-ea81-446b-ba2a-4f7ebe2811c3@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

Hi!

I'm sorry but I am not English and I speack English very
bad.

My question is: How connect a PC Embedded to Vending
Machine? I know
that exist a protocol MDB that is used by vending machine,
but this
conector is different to pc conector (RS232, USB, i2c,
etc). Can I
connect a PC Embedded by MDB? How?

Anybody understand me?

Thanks you!

We understand you.

Read the spec to understand what is required to connect.

However, even once you have done the hardware to be able to
connect to a
PC's RS232 port you will, more than likely run into the
problem of the 9bit
char format not being supported on a std PC serial port.

You can fudge it using the mark/space parity control but it
is not very
nice.

Why don't you use ccTalk instead?www.cctalk.org

regards
PhilW

Thanks you.

I dont understand all, what is "ccTalk"??

regards.
Juanma.- Ocultar texto de la cita -

- Mostrar texto de la cita -

I read a little about spec of "ccTalk", and this is other
protocol,
no?

I need "to talk" with a vending machine. The standard of vending
machine is the MDB (i think).

Are you understand me?

Thanks you.
regards.

Here is a USB to MDB bridge
:http://www.geocities.com/bonusdata/analyzer/mdb_interface/mdb_interface.
htm
(sorry for the spanning)

Here is the protocol :http://www.vending.org/technical/MDB_3.0.pdf

www.vending.orgiswhereyouneed to go for any info about MDC/ICP-
Ocultar texto de la cita -

- Mostrar texto de la cita -

Thanks you!!

I know this all, but the "USB to MDB" is not a good solution for me,
should be others solutions...

I am interesting in ccTal PhilW but i dont understand how apply this
to the vending machine.

If the vending machine does not speak CCTalk then there is no way to
apply it at all, in this case. MDB/ICP is the way you will have to go.
CCTalk was designed more along the lines of gaming systems and MDB was
designed for vending machines and the like. Not that you couldn't use
CCTalk in a vending machine, but MDB was standardized for use in them
(vending machines) long ago.- Ocultar texto de la cita -

- Mostrar texto de la cita -

Oh James Beck, i think that you have reason.

My problem is how comunicate the pc embedded with vending machine with
the protocol MDB... If the unique solution the "MDB --> USB adapter"?
If you sum the price that a pcembedded+adapter ... for one for machine
is very expensive no? it must of having another solution, no?

Thanks you!
regards.

Well, if you doing a one off machine, there will never be any economy of
scale. If I were doing a single machine/test station, I wouldn't balk
at paying the price for the adapter. If I were doing thousands of them
I would look at doing something more task specific and cheaper. You can
implement the protocol yourself with some kind of adapter for the PC and
a communications library, but that would be what the specification is
for.- Ocultar texto de la cita -

- Mostrar texto de la cita -

Oh, I see that you understand me :)

I need to create adapter for MDB to any port (serial?) the PC ... it
is difficult? I know computer science, but the electronic... :( any
idea?

Thanks you!
regards.

An adaptor is not an easy thing to do, simply due to the fact you need to
maintain the timing specifications of the MDB protocol. An adaptor that just
recieves a command from the PC, re-formats it for MDB and then sends it on,
waits for the response and forwards that to the PC will easily break the
timing criteria of the protocol, considering that each char takes 1mS to
transmit or receive.

Concerning USB adaptors. Can be good providing they support, and implement
the mark/space parity support correctly. However, you still have to provide
low level coding to fudge the 9 bits via the mark/space parity. In addition
you will be required to add timing delays to ensure the parity changes are
sent over USB before transmitting the next data or parity change. We have
had success with the CP2102 from silicon Labs. It is sure however, from
experience, that supporting MDB over USB is a lot more painful than a
standard serial port.

Another alternative is to acquire an add-on serial port that natively
supports 9 data bits at the hardware level. Not cheap, hard to find and
expensive.

As for the vending machine implementation, you have not said, but I conclude
that YOUare building the vending machine and YOU therefore have control over
the protocol to use. Unless by some specification requirement that you use
MDB, I see no reason why you cannot use ccTalk. I believe the "protocol" is
purely for internal machine use, aimed at connecting all peripherals to a
host controller, namely your embedded PC. Any external communications is
usually by some other communications link, modem, ethernet, wifi, etc. Why
ccTalk? It's simple and most importantly can be easily supported by any PC
serial port, USB adaptor etc that supports the standard 8bit char length. It
could be any other protocol besides, that uses the 8bit data length as well.
It's just that ccTalk is well documented, well supported and widely used.

We produce products that support both MDB and ccTalk in addition to others.
We much prefer ccTalk for its non requirement of the 9bit data format.

regards
PhilW- Ocultar texto de la cita -

- Mostrar texto de la cita -

Oh, no, I am not a building the vending machine and I haven't control
over the protocol to use, it is the problem. I need use the protocol
standard in the most vending machine, that is, MDB.

Do you understand me PhilW? Sorry for my English.

regards.
.

Relevant Pages

  • Re: How connect PC Embedded to MDB (Vending Machine)
    ... that exist a protocol MDB that is used by vending machine, ... connect a PC Embedded by MDB? ... CCTalk was designed more along the lines of gaming systems and MDB was ...
    (comp.arch.embedded)
  • Re: How connect PC Embedded to MDB (Vending Machine)
    ... that exist a protocol MDB that is used by vending machine, ... conector is different to pc conector. ... connect a PC Embedded by MDB? ... Here is a USB to MDB bridge:http://www.geocities.com/bonusdata/analyzer/mdb_interface/mdb_interface. ...
    (comp.arch.embedded)
  • Re: How connect PC Embedded to MDB (Vending Machine)
    ... conector is different to pc conector (RS232, USB, i2c, etc). ... connect a PC Embedded by MDB? ... I read a little about spec of "ccTalk", and this is other protocol, ... I need "to talk" with a vending machine. ...
    (comp.arch.embedded)
  • Re: How connect PC Embedded to MDB (Vending Machine)
    ... that exist a protocol MDB that is used by vending machine, ... conector is different to pc conector. ... connect a PC Embedded by MDB? ... Here is a USB to MDB bridge:http://www.geocities.com/bonusdata/analyzer/mdb_interface/mdb_interface. ...
    (comp.arch.embedded)
  • Re: How connect PC Embedded to MDB (Vending Machine)
    ... that exist a protocol MDB that is used by vending ... connect a PC Embedded by MDB? ... low level coding to fudge the 9 bits via the mark/space parity. ...
    (comp.arch.embedded)