-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Thu, 20 Jan 2011 18:06:24 -0500 V G wrote: [snip] > * I would like to implement MODBUS over XBee. Would this be > relatively easy to interface to a PIC32 on the RTU end? I don't know anything about MODBUS. In transparent mode, however, an XBee is preconfigured with the address of a peer device and acts as a farily dumb serial pipe which takes 8-bit asynchronous serial data. >=20 > * Also, how would I go about connecting an XBee module to the desktop > computer? Are there any adapters available? Digi sells XBee PKG-U boards, which are small USB dongles with an FTDI on them and a socket into which you can plug an XBee. >=20 > * Currently, the MODBUS software is communicating to a physical > serial port (RS232) on the computer which is connected to a RS485 > converter module which is connected to the multidrop cable. > Therefore, I'd need to emulate a serial port on the desktop which > communicates with the XBee. How difficult would this be to do? Is > this *unheard* of? See above, Digi PKG-U with FTDI. However, the multidrop issue changes things a bit. While XBees can do multipoint communication, the sane way to do this is in "API mode", where you use a frame structure for communication which includes the address of the receiving XBee (depending on how much modification you want/are able to make to each part of the system, this may or may not be reasonable for you to use). Alternatively if there are relatively few devices to communicate with (say just 2 or 3) you could just have a separate dongle on the computer for each device, preconfigured with the corresponding device's XBee's address, and use them in transparent mode as completely independent communication channels. Chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.16 (GNU/Linux) Comment: GnuPT 2.7.2 iEYEARECAAYFAk05O5sACgkQXUF6hOTGP7evpgCfUf+aCxe3iZqWz3jEk0yCZBBK b4UAoIxo2fc9g36nqt72KdjZg3Dfetlr =3Diy+r -----END PGP SIGNATURE----- --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .