Etherserial Link driver for Linux kernel 2.6.x

1. Make sure that you have the Linux kernel source installed. The kernel
source tree is usually under '/usr/src' directory. If you don't have it
installed, install the kernel source package from the CD/DVD of your Linux 
distribution. The kernel source files should correspond to the kernel version 
and configuration that your Linux box has running. Also you should have the
GNU C compiler installed.

2. In your home directory, make a new subdirectory for the Etherserial Link driver.

# mkdir esl
# cd esl

3. Copy esl.tgz to that directory and unpack it

# tar -xzf esl.tgz

4. Run 'make' utility to compile the driver

# make

5. Check the 'error.log' file. If it has zero length and there is an
'esl.o' file, you have successfully compiled the driver and you 
can go to step 6. If you have seen error messages from the 'make' utility or 
there are error and/or warning messages in 'error.log' file, you can try to 
figure out what is wrong on your own or send a detailed report (including all 
error and warning messages) to the technical support team.

6. Install the driver.

# make install

7. Try to start the driver.

# modprobe esl

8. If the driver started sucessfully, remove it and start it again with new parameters 
corresponding to the network settings you chose for the Etherserial Link 
devices. In the example below, it's assumed there are two dual port ESL units on the LAN: 
the first box has IP address 192.168.0.35 and the second box has IP 192.168.0.36, 
both of them have TCP ports 4098 assigned for Serial 1 and TCP port 4097 for 
Serial 2.

# rmmod esl
# insmod esl.o ip=192.168.0.35:4098,192.168.0.35:4097,192.168.0.36:4098,192.168.0.36:4097

Alternatively you can add this line with parameters to '/etc/modules.conf' file.
The line should look like:

# options esl ip="192.168.0.35:4098,192.168.0.35:4097,192.168.0.36:4098,192.168.0.36:4097"

In this case, 'modprobe esl' will start the driver with parameters from 
modules.conf file.

Note1: The factory default IP address is 192.168.0.35. If you don't know the IP 
address of your particular box, connect the box to the local network and run
the 'lsesl' utility. It will print the MAC address and IP address of the box. If you
have a few boxes on the network, you can distinguish between them by MAC address 
(every unit has a label with the MAC printed on it). To get detailed help on the 
'lsesl' utility, run 'lsesl -vvvh'.

Note2:  Connect one box at a time to the local network, to prevent
IP conflicts. Use a telnet session or web browser to set up the network 
parameters. The box should be in "Driver mode" (old firmware may refer to 
this mode as "Windows driver") to work properly with the driver. 

9. Now you can work with remote etherserial ports just like with local ones. 
The only difference is that local serial ports have names /dev/ttyS0, 
/dev/ttyS1, etc. and ESL serial ports have names (by default) /dev/ttyES0, 
/dev/ttyES1, etc.

10. If everything works fine, add the line to your start-up script in order to 
launch the driver at system bootup.

Alternatively you can add the line with alias name to '/etc/module.conf' file,
and the kernel will start the driver as soon as any application requests the
port. The line should look like:

# alias char-major-247 esl