Ethernet Testing

How to set up the Ethernet, and how it is used


There is one Ethernet port on the board, which has a variety of uses.
The Ethernet is set 100M, and this cannot be changed.  The ETH LED (yellow) on the board, and the left hand LED in the ethernet socket work together, to indicate the following:
LED off - No connection
LED on - Connection present
LED blinking - data being transferred.
The Ethernet port can connect in TCP mode, or  it can just send data in UDP mode.  The usage of the ethernet port is determined by the Option Switch. 
Each board has it's own MAC address, and this is printed on a label on the board.  The MAC address is also the serial number of the board.

Using the Ethernet

The Ethernet can be used for communicating with a computer running JMRI, RocRail or MERG FCU.  It can either be connected directly, through a router, or even through a wireless link.  The IP Address of the ethernet must match your network's requirements, and you should have set up the IP Address prior to trying to use the port.  Remember, at any time, you can open up a Command window on your computer, and run a Ping command, to check that the ethernet port is indeed connected.  Using the command window, you can also alter the IP address without having to touch the hub.

MAC Address

The MAC address (Media Access Control Address) is nothing to do with MAC as the operating system or reference to Apple products.  The MAC address is a 48 bit number which is unique to a specific piece of hardware, and is used in Ethernet to distinguish it from any other piece of hardware.  The Hub has its own unique MAC address, and you can find it on the printed label, as a series of 6 two digit hex numbers.  On this website, MAC is only used to refer to the MAC address, any reference to Apple operating systems is referred to as Apple.

Running a Ping Command

Ping is a way of sending a message over ethernet, and receiving a reply, to make sure the connection is working.  It does not interfere with any other messages.
In all operating systems, you should start by opening a command window.  If the IP address you have set the hub to is, then type
ping or in Linux ping -c 4
and your computer will ping the Hub 4 times, and you will get a message back saying the ping has worked.  The Linux -c 4 bit is important, otherwise Linux will just continue to ping endlessly, unless you shut down the command window!.
If you have forgotten what IP Address you have set the Hub to, take a note of the MAC address (printed on the Hub), and then in the command window type
arp -a  This will bring up a list of IP Addresses against MAC address, and you can then note the IP Address, and then do a Ping.

Setting the IP Address

You can set the IP address of the Hub in Windows, Apple or Linux by using the command window.  The MAC address is printed on the hub, and is unique to each hub.  Take a note of this, and then you can use the arp table and the ping command to set the address.
The steps are the same in any operating system, but the exact commands vary slightly.
The steps are:
1] Populate the arp table with the MAC address and the desired IP address.
2] Send a ping command with a length of 40 to the hub.
3] Send a ping command with a normal length (32) to test the connection.