Table of content
Getting the Blue Heat/Net Linux Host Driver
The latest Connect Tech Inc. drivers can be found at:
The filenames of the driver install packages have the following format:
<24|26> – Indicates that the driver is for 2.4.x or 2.6.x kernels.
<rel> – Indicates the release version of the driver.
For example, the file BHN-LHD-24-2.3.tar.gz contains the version 2.3 release
of the driver for 2.4.x kernels.
Installing the Driver
Before installing the driver the Blue Heat/Net unit should be configured:
1) Connect the Blue Heat/Net unit to the network and make sure it can
– If it is connected, but cannot be reached, try using the serial
configuration manager to reconfigure the network settings.
– See the Blue Heat/Net user manual for more details.
2) Set the line modes of each port (232, 485-HD, 485-FD, etc).
– This is a vital step in setting up correct operation with the driver.
– This option is available under each of the configuration managers.
– A brand new BHN unit has the line modes set to “undefined” which will
cause each port not to function.
3) Reboot the Blue Heat/Net unit and try pinging its IP address.
– If the ping succeeds the driver is ready to be installed.
– If you cannot ping, check for firewalls, blocked TCP ports, etc…
check that you are on the same sub-net as well
Note: Please check the version of firmware running on your BHN unit to make sure you are running at least v1.18 or newer.
To check for this, telnet into the box from your PC.
#telnet xxx.xxx.xxx.xxx (IP address of BHN)
login : tcm
-this will display general BHN info
– look for the field “uClinux package (in Flash) version …..”
-exits from the telnet configuration manager
If you are running firmware older than 1.18, you can update it from Connect Tech’s ftp site, or from a local ftp server (ideal if the BHN is in a remote location).
To update from Connect Tech’s ftp site, your BHN will require access to the internet. You will also need the “Gateway IP” and “DNS Server IP” fields filled in (see manual for more information).
To update via local ftp, please refer to Knowledge Base Article #304, which can be found on our website:
Once the Blue Heat/Net unit has been configured and is available on the
network, the next step is to unpackage and install the driver:
4) Login as, or otherwise become, root.
# su –
5) Unpackage the driver by unzipping and untarring the install package:
# tar -xzf BHN-LHD-Install-<24|26>-<rel>.tar.gz
6) Install the driver by running the install script and following the on
# cd BHN-LHD-Install-<24|26>-<rel>
**** Note for Ubuntu users *******
If you see shell errors when running this script, please refer to Knowledge Base Article #303:
Upon succssful completion of the install script the driver will be installed
according to the options selected.
Updating the Driver
A previous installation of the driver can be upgraded by following the steps
outlined in section 1.2, using a different install package.
Configuring the Driver
The driver is configured using text-based configuration files. These files
control how a given serial port on a Blue Heat/Net unit is mapped to a virtual
serial device in the Linux Host Driver.
### Example of a mapped 8 port BHN unit
# Blue Heat/Net (8 ports) 126.96.36.199
# Serial #997 MAC 00:0c:8b:00:03:e5
# Hostname BHN00000997.connecttech.local
0 188.8.131.52 49152 1 100 1
1 184.108.40.206 49152 2 100 1
2 220.127.116.11 49152 3 100 1
3 18.104.22.168 49152 4 100 1
4 22.214.171.124 49152 5 100 1
5 126.96.36.199 49152 6 100 1
6 188.8.131.52 49152 7 100 1
7 184.108.40.206 49152 8 100 1
For a full description of these fields, read to comments found in /etc/bhn.conf
Special Note: If you would like your Virtual Serial Ports to “auto-reconnect” in case of a loss of connectivity of power to the BHN, the last field must be filled in with a ‘1’. The default is ‘0’, and will not reconnect. For example, if your software is constanly reading in data from a BHN port, and the BHN looses power momentarily, the software will have to CLOSE and REOPEN the port before data transmission resumes. With ‘auto-reconnect’ enabled, the driver will do this automatically.
One method of generating a configuration file is to use the provided
autodiscovery tool. This tool attempts to detect all Blue Heat/Net units
available on the network.
To execute the autodiscovery tool, the driver must be running. Reading from
/proc/bhn/autodiscover will return information on all detected Blue Heat/Net
units. This data is in the format of a configuration file and can be directly
used to configure the driver.
For example, to generate a configuration file using the autodisovery tool:
# cat /proc/bhn/autodiscover >/etc/bhn.conf
To change any parameters used in discovering Blue Heat/Nets, echo in the
parameter with the new value. For example:
# echo “timeout=10” >/proc/bhn/autodiscover
Parameters include “network”, “port”, “poll” and “timeout”. For a full
description, please refer to the first few lines of any autodiscover.
The configuration of the driver is done by writing configuration data to
/proc/bhn/config. The format of the configuration data is that of a
configuration file. Reading from /proc/bhn/config will return the driver’s
current configuration, also in the format of a configuration file. The driver’s
configuration can be erased by writing the keyword “clear-mappings” to
To configure the driver using a configuration file:
# cat /etc/bhn.conf >/proc/bhn/config
To configure the driver using the autodiscovery tool directly:
# cat /proc/bhn/autodiscover >/proc/bhn/config
To retrieve the driver’s current configuration:
# cat /proc/bhn/config
To clear the driver’s current configuration:
# echo “clear-mappings” >/proc/bhn/config
You cannot map a configuration file into /proc/bhn/config if one has already been done. You must use the “clear-mappings” command, and then cat in your new configuration file.
Some statistical information on the driver’s virtual serial devices can be
obtained by reading from /proc/bhn/stats.
For example, to retrieve the driver’s statistical information:
# cat /proc/bhn/stats
Connect Tech provides three scripts which can be used to start and stop the BHN module. They are found in:
#/usr/cti/BHN-LHD-26-2.#/scripts -for 2.6 kernels
#/usr/cti/BHN-LHD-24-2.#/scripts -for 2.4 kernels
bhn-init (start | stop | restart) – this script will stop and start the bhn module (remove device nodes, clear mappings in /proc/bhn/config, stop the module -> create the device nodes, map /etc/bhn.conf back to /proc/bhn.conf, start the bhn module)
If ports ever become unresponsive, this is a good script to run. It is also added to /etc/init.d by default, so it runs everytime on boot up.
Testing the Driver
Devices nodes for the driver’s virtual serial devices are of the format
Run a local loopback test between two ports using a standard serial terminal
program (i.e. minicomm) and a null modem cable.
Customer Support Overview
If you experience difficulties after reading the manual and/or using the
product, contact the Connect Tech reseller from which you purchased the product.
In most cases the reseller can help you with product installation and
In the event that the reseller is unable to resolve your problem, our highly
qualified support staff can assist you. Our support section is available 24
hours a day, 7 days a week on our website at:
http://www.connecttech.com/sub/support/support.asp. See the contact information
section below for more information on how to contact us directly. Our
technical support is always free.