Alpha Technologies Cordex Controller Ver.3.1x - Manual (Page 102)

0700015-J0 Rev B 100
8. CXC Communications Menu Parameters
This chapter provides definitions regarding Ethernet, IP Addresses, and CXC communications (port)
configurations.
8.1 Ethernet Port Configuration
8.1.1 About IP Addresses
IP stands for Internet Protocol. Every device on an IP-based LAN or WAN network (including the CXC
controller, as well as PCs, and routers) requires an IP address to uniquely identify the source node or
destination node for packets sent across the network. This applies to WAN and LAN connections. There
are two ways of assigning an IP address to a network device: Static IP Address and Dynamic IP Address.
8.1.1.1 Static IP Address
A static IP address is a fixed IP address that the user assigns manually to the CXC or to a PC or any other
device on the network. This address remains valid until the user disables it, thus ensuring that the device
will always have that same IP address until the user changes it. Check with the LAN administrator to see
if they have allocated a Static or Dynamic IP address for the CXC on the network.
8.1.1.2 Dynamic IP Address
A dynamic IP address is one that is automatically assigned to any device on the LAN network. This ad-
dress is called “dynamic” because it is only temporarily assigned to the CXC, PC or other network device.
After a certain time, it expires and may change. If a PC logs onto the network (or the Internet) and its
dynamic IP address has expired, the DHCP server (see below) will assign it a new dynamic IP address.
DHCP Server (8.1.1.5) may choose to assign the same IP address every time based on the MAC ad-
dress.
8.1.1.3 Subnet Mask
The Subnet Mask (also known as the Network Mask) determines which portion of an IP address is the
network portion, which portion is the host portion, and directs the CXC regarding communications via the
Default Gateway (8.1.1.4).
If not connected to CXC via crossover, hub, or switch, then misconfigured subnet and gateway will result
in the inability to communicate with the CXC.
8.1.1.4 Default Gateway
This IP address should be the IP address of the gateway device that enables contact between the CXC
and the remote network or host. If the destination node is not in the local sub network, the protocol is sent
to the default gateway (and may not be required for a small network).
8.1.1.5 DHCP (Dynamic Host Configuration Protocol) Servers
A DHCP server can automatically assign a new IP address to the CXC (or any other network device that
uses dynamic IP addressing). In this case, the CXC is called the DHCP client. DHCP frees the admin-
istrator from having to assign an IP address manually every time a new user is added to the network. A
DHCP server is usually a dedicated network device such as a router or firewall.
By default, the CXC is configured to enable the DHCP client (the “Obtain Address Automatically” check-
box is selected). If the DHCP Client is enabled, then the DHCP server automatically provides the Subnet
Mask and Default Gateway parameters. If the DHCP client is disabled (clear checkbox for “Obtain Ad-
dress Automatically”) then it is possible to explicitly specify the Subnet Mask and Default Gateway.