To set up the addresses manually uncheck the” Get Address Automatically” box and enter the
addresses in the appropriate edit boxes. Each box must contain a number in the range 0 to
255. The default values are:
IP Address: 192.168.0.6
Gateway Address: 192.168.0.1
Submask: 255.255.255.0
These values should be OK for small networks with only one or two computers and a gateway
router.
If you need to change them you will need to ascertain the values from the network. For local
networks there are three address ranges:
10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255
The best way to find free addresses is to log on to the gateway router as this will keep track of
all the attached devices. It will also show its own IP address which should be used as the
Gateway Address.
You can find the settings on any local PC running Windows by going to the command prompt
and typing “config”. This will return the IP Address of the PC, the Gateway Address and the
Submask. If you only have one PC and gateway router then use the last two values for the
Gateway Address and Submask and increment the last digit of the IP Address by 1.
Port Number
The port number is used as part of the network interface. This can be set anywhere in the
range 1 to 65535. However values below 1024 should be avoided as these are generally pre-
allocated to well known services.
Connections
The connections section defines how the link is established and maintained.
In client mode the Netiom-UDP will periodically send out a network packet even if the link is
not established. Data will be transmitted whenever a change occurs on the inputs or when a
serial message is received. If there has been no change for a period defined by the Update
Period then a message will be transmitted as a heartbeat.
If client mode is not select messages are not transmitted until the link is established.
Messages will then be sent in the same way as in client mode.
When in client mode the Netiom-UDP will need to know the IP address to connect to the other
end of the link. Two methods are available. If Use Broadcast Address is selected Netiom-UDP
will transmit a broadcast to all devices on the network. The device at the other end will
recognise this message and return with a reply indicating its own IP address. The originating
device will then use this new IP address for further communication. Note that this method is
only suitable for local area networks as broadcasts are not allowed to transverse gateways.
The second method is to supply an IP address. In this case the originating Netiom-UDP will
establish contact directly with the other end. This method must be used for wide area
networks such as the internet.
Serial Port
With the programming link in place the serial port always runs at 19200 baud.
