Hi James,

I'm very interested in this project described here.  Sounds like you want
something to give your PC  a window into the DH485 network, and access to
the devices on that network.  Also sounds like a lot of fun.  I've worked
with Allen Bradley & other PLC's quite a bit in the past, but never with
the DH485 network.  I would love to learn this, however, and this kind of
project seems the perfect way.

I work full time for a regular company doing regular electrical engineering
work (Creo Products) but have my own business on the side (Agile Controls)
doing projects just like this one, mostly with PIC's.  I just finished one
project for a greenhouse ventilation controller, and am in the middle of a
second small project with a third one in the queue.  I've got facilities
for small quantity through-hole manufacturing, in the order or 10's to
100's, if you are considering getting a hand-full made.

I've got a B.S.E. from Calvin College in Grand Rapids, Michigan (ever heard
of the place?), then moved out here to Vancouver in '92, and have been
doing electrical engineering ever since then.

What kind of timeline are you looking at?  I suspect I would be able to
finish something like this in late April, but my other projects are pretty
low priority so maybe some shuffling could happen.

Do you have more details you could send me on what kind of an interface and
commands you are looking for?  Requirements for a project like this would
change dramatically depending how nice of a user interface you are looking
for.  For example, are you interested in nice menus coming from the PIC and
formatted device lists, over the RS232, or will cryptic little commands be
enough?  Any more details on the interface would be great.  Fax or email
would be great.

-Ed VanderPloeg
evanderploeg@creo.com
Agile Controls.
ph. (604) 581-4203
fx. (604) 581-0661

At 07:40 PM 2/24/97 PST, you wrote:
>I would like to contract someone to create a Microchip microcontroller
>based interface to the Allen Bradley DH485 network. The communication
>protocol is documented in one of their publications but I don't have the
>time to dedicate to learning it. I have the following requirement / wish
>list for this "Interface Microcontroller":
>
>- A Microchip microcontroller (STAMP? or 16C/17C series processor) based
>interface to communicate with a SLC500 Programmable Logic Controller (PLC)
>at 9.6 or 19.2KBaud.
>
>- Must be able to re-establish communications upon disconnect or error and
>must incorporate the protocols CRC.
>
>- Communications to this "Interface Microcontroller" from another
>microcontroller to be either RS232 or IC2.
>
>- I would like to be able to send commands to tell the interface
>microcontroller which file type and how many words to read or write.
>
>- I would like to be able to communicate in the DH485 network that could
>consist of 2 to 31 devices addressed as device numbers 0 - 31.  I would
>like to be able to set the "Interface Microcontrollers" device address over
>the RS232 or IC2 communication channel.
>
>Would require a breadboarded, working prototype.
>
>If you are familiar with Allen Bradley's DH or DH485 communications and
>would like to quote on the above project feel free to call or send e-mail.
>
>
>James_Fillmore@XYZTech.com
>http://www.XYZTech.com
>XYZ Technologies, Inc
>5510 Gatewood
>Sterling Heights, MI 48310
>(810) 939-9715 (fax (810) 939-4514)
>
>