wood@drift.dec.com (John F. Wood) (11/01/90)
I am looking for networking software to allow an IBM PC to connect to
several (1-30) remote micro-controllers using a single serial port. The
software needs to allow for individual messages to be sent from and received
by the PC. I will need to write the compatible software for the
micro-controllers (which currently use Intel 8051 microprocessors), so the
protocol specs must be provided with the PC software.
While I can (and have) implemented simple software to do some of this, I
would like to find software that has already implemented error checking in
all (or most) of its various forms, as well as the multiple remote support.
The communications can either be done via polling the remotes, or by a
collision detect scheme similar to that employed by Ethernet. The
electrical connection will be RS-485 which allows multiple devices on a
single line.
I've seen several network packages which implement file transfer and remote
device support between PCs, but I'm not familiar with any that allow
programmers to send individual messages. The PC needs to be able to act as
a central control facility, data storage device, and master scheduler for
the remotes, through my programming.
FYI, the application is adding intelligence to a house with distributed
controllers interfaced to many different sub-systems.
Any ideas?
Thanks,
John
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John F. Wood | EIS Engineering
Digital Equipment Corporation | ARPAnet: wood@acesmk.enet.dec.com
Continental Blvd. | EASYnet: ACESMK::WOOD
MKO2-1/J12 | Usenet : ...!decwrl!acesmk!wood
Merrimack, NH 03054 | AT&T : (603) 884-4686
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Disclaimer: Views expressed herein are my own and do not necessarily
reflect those of my employer.
----------------------------------------------------------------------jamesp@world.std.com (james M peterson) (11/02/90)
Look at Alpha Products Inc. They make excellent low cost controllers of all types. They also have multi-node serial controllers for their stuff and probably something for your stuff too. 242 West Av. Darien, CT 203/656-1806 UK: 0294/605296 Scotland Scan: 04/41 8351 Norway Just a very satasfied customer. jamesp@world.std.com "Reality is not an industry standard"
jcburt@ipsun.larc.nasa.gov (John Burton) (11/03/90)
In article <1913@shodha.enet.dec.com> wood@drift.dec.com (John F. Wood) writes: > >I am looking for networking software to allow an IBM PC to connect to >several (1-30) remote micro-controllers using a single serial port. The >software needs to allow for individual messages to be sent from and received >by the PC. I will need to write the compatible software for the >micro-controllers (which currently use Intel 8051 microprocessors), so the >protocol specs must be provided with the PC software. > >While I can (and have) implemented simple software to do some of this, I >would like to find software that has already implemented error checking in >all (or most) of its various forms, as well as the multiple remote support. > >The communications can either be done via polling the remotes, or by a >collision detect scheme similar to that employed by Ethernet. The >electrical connection will be RS-485 which allows multiple devices on a >single line. > >I've seen several network packages which implement file transfer and remote >device support between PCs, but I'm not familiar with any that allow >programmers to send individual messages. The PC needs to be able to act as >a central control facility, data storage device, and master scheduler for >the remotes, through my programming. > >FYI, the application is adding intelligence to a house with distributed >controllers interfaced to many different sub-systems. > >Any ideas? > >Thanks, > >John > I know this probably won't help much, but another possibility is to go with another interface instead of the serial line. The serial port on a PC is not really designed to do what you want to do efficiently. The IEEE-488 (or GPIB) interface is commonly used for controlling several pieces of lab equipment from a single PC. This particular interface was designed to do what you're trying to do, one master machine controlling several slave machines. Several companies manufacture entire product lines for just this purpose. Two that come to mind right away are Data Translation and Metra Byte Corp. I've never done business with either (in the past few years) but it might be worth your time to look into it. John Burton (jcburt@cs.wm.edu) (jcburt@ipsun.larc.nasa.gov)
bomgard@iuvax.cs.indiana.edu (Tim Bomgardner) (11/07/90)
In article <1913@shodha.enet.dec.com> wood@drift.dec.com (John F. Wood) writes: > >I am looking for networking software to allow an IBM PC to connect to >several (1-30) remote micro-controllers using a single serial port. I haven't seen anything like this either, so I'm in the process of creating such a system for my own use. While it will work on (almost) raw RS-232C ports, (a diode and a couple resisters in the DB25 shell), I've already fabricated the pc boards which will allow (for my purposes) an unlimited number of machines on the network (high impedance op amps = no load on the cable). The boards almost fit in the shell, but not quite. The software consists of a serial port driver that I am modifying for CSMA/CD, and (still on paper) a standard OSI-type Data Link Layer. On top of that, anything will be possible. My intention is to add a file server and redirector, and a Remote Procedure Call package (which is what I'm really interested in). At 56KBPS (maybe 115KBPS?), it isn't exactly gonna be Ethernet (or even AppleTalk), but the network will only cost me about $5 per node. Let me know if you find anything to suit your requirements. I'd be interested in knowing what else is out there, and in any comments or suggestions about my solution.
ygrignon@sobeco.com (y.grignon) (11/16/90)
In <1913@shodha.enet.dec.com> wood@drift.dec.com (John F. Wood) writes: >I am looking for networking software to allow an IBM PC to connect to >several (1-30) remote micro-controllers using a single serial port. The > ... >electrical connection will be RS-485 which allows multiple devices on a >single line. > ... >FYI, the application is adding intelligence to a house with distributed >controllers interfaced to many different sub-systems. >John F. Wood You should subscribe to Circuit Cellar Ink. Their team includes Steeve Ciarcia (used to write for Byte) and Ed Neesley. Together they have put together your complete application, including the PC software. Get the back issues. Yves