     ****************************************
     *      HAL RTNET DOCUMENTATION         *
     ****************************************
     
     INDEX:
     - FILES
     - NOTES
     - EXAMPLE
     
     
     FILES
     
       Module:
       - hal_rtnet.c			// See hal_rtnet.c for module parameter specifications
       
     
       Scripts:
       
       For start WITH EMC2 (first start EMC):
       - rtnet_emc <NIC module name>	// Start-up script for RTnet
       
       For start WITHOUT EMC2:
       - rtnet <NIC module name>	// Start-up script for RTnet
       - realtime_rt <start|stop>	// Start-up script for the real-time system
       
       
       Config files:
       
       - TEST_SEND.hal			// Sample / test HAL configuration file (bin/halcmd -f TEST_SEND.hal)
       - TEST_RECV.hal			// Sample / test HAL configuration file (bin/halcmd -f TEST_RECV.hal)
       - rtapi_rt.conf			// real-time configuration file (module start-up list)
     
     
     NOTES * **
     
       * See also hal_rtnet.c for notes on installation of the module.
       
       ** See also RTnet documentation for the available NIC drivers.
       
       This module will only work with RTAI, since RTnet supports Xenomai & RTAI and EMC2 supports
       RTAI and RT-Linux.
       
       So far this module is only tested on a 2.6.15 kernel patched with RTAI-3.3-CV with
       EMC 2.0.1 release and RTnet 0.9.3.
       
       So far we have no absolute numbers on the module's performance - it won't take long. In the
       meanwhile we can say that this module will probably have a delay of around +/- 1 millisec,
       depending on your set-up (it is very well possible that this number will be significantly
       decreased in the future).
       
       Install RTnet in /usr/local/rtnet
       
       Edit /usr/local/rtnet/etc/rtnet.conf to match your system. Update the TDMA cycle to match
       the thread hal_rtnet runs in (for a 1.000.000 nanosec thread (1 millisecond) we used a 0.5
       millisecond TDMA cycle)
       
       Make sure to use the rtai_ksched module when starting either EMC2 or realtime_rt (see
       rtapi.conf / rtapi_rt.conf) instead of rtai_lxrt
       
       Edit the script & configuration files to suit your system.
       
       Don't forget to specify fp_period when loading the module - it won't run in a thread if
       you don't.
       
       
     EXAMPLE (after configuring /usr/local/rtnet/etc/rtnet.conf and writing your HAL file)
     
       Step 1:
       Start EMC on both computers: scripts/emc
       
       Step 2:
       Start RTnet on both computers (we use the realtek 8139 NIC): scripts/rtnet_emc 8139too
       This will make a connection and wait for you to shut it down when you're done by pressing 
       enter. Now open a new shell for Step 3.
       
       Step 3:
       In the EMC2 directory of your recieving machine, type: bin/halcmd -f TEST_RECV.hal
       In the EMC2 directory of your sending machine, type: bin/halcmd -f TEST_SEND.hal
       If you are accidently running a tail -f on /var/log/messages you will probably see 
       some -105 errors on the sending side and some -110's on the recieving side. No worries,
       that's normal :-)
       
       Step 4:
       Watch your HAL pins!