From: Cigol C Procedure for installing the rs485 Driver in Linux -------------------------------------------------- i) First untar the ip_over_rs485.tgz using command `tar xvzf ip_over_rs485.tgz` in your working directory. ii) Now issue `locate modversions.h` for locating the modversions.h file in the source directory. Typically for a 2.4.2-2 kernel the output is as follows: /usr/include/linux/modversions.h /usr/src/linux-2.4.2/include/linux/modversions.h iii) Now open the Makefile and change the location of modversions.h to `/usr/src/linux-2.4.2/include/linux/modve rsions.h` and source include as `/usr/src/linux-2.4.2/include`. Note for different kernel source directory make appropriate change. iv)After successful compilation check whether rs485.o object file is created. v)Issue setserial -a in root mode to get the irq and iobase details of your serial port. Ex `/bin/setserial -a /dev/ttyS0` vi) For iobase=0x3f8 and irq = 4 issue insmod commad as show below in the slave terminal. `/sbin/insmod -mv rs485.o iobase=0x2f8 irq=4 nodeid=1` For master node id is 0. Check with `/sbin/lsmod` whether the module rs485.o is loaded. vii) The whole idea of this driver is to create an interface ip for each master-slave interface since rs485 supports only half duplex communication. Hence the next step is to associate an ip and point to point ip address for master-slave communication. viii) In master by default from rs00 - rs14 interfaces are created. From rs01 interfaces can be used for point to point communiation between slaves. Use ifconfig to associate point to point ip address on rs01. For ex: `ifconfig rs01 10.4.7.177 pointopoint 10.4.7.176` ix) In slave do the same and set an IP address on rs00. For ex: `ifconfig rs00 10.4.7.176 pointopoint 10.4.7.177` Note the point to point IP address is the IP address of the other. x) Issue `/sbin/ifconfig -a` to verify the interface commands issued. Ex: #/sbin/ifconfig rs00 rs00 Link encap:Serial Line IP inet addr:190.4.7.177 P-t-P:190.4.7.176 Mask:255.255.255.255 UP POINTOPOINT RUNNING NOARP MTU:150 Metric:1 RX packets:17277 errors:0 dropped:0 overruns:0 frame:0 TX packets:17257 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:10 Do the same is master and verify the results. xi) Now your done with interface configuration and start IP applications to check the IP over Rs485. For ex:Issue ping command `ping 10.4.7.177` in the slave terminal for checking the connection. Please contact the following address for any feedbacks. Author:Ronald Schmidt Address:Ronald Schmidt