Tracelink User Manual 21
modification of a basic theme, which is that of connecting one or more PCs through a
Hub to one or more Tracelinks.
In order to connect these devices to the Hub, you will need to use the provided
straight-through Ethernet cable. The straight-through cable, which is the “standard”
Ethernet cable, is used to connect devices of different types together, such as a PC to
a Hub, or a Hub to a Tracelink.
At this point it once again becomes necessary to program the Tracelink with valid IP
numbers, the process for which is described in greater detail in the following section.
However, it is important for the Tracelink and the PCs to have matching Subnet and
Gateway IP numbers, and for each to have a unique IP number on the network. An
example of a setting for above is as follows:
IP Number Gateway IP Subnet Mask
PC1 192.168.100.1 192.168.100.3 255.255.255.0
PC2 192.168.100.2 192.168.100.3 255.255.255.0
Tracelink 192.168.100.4 192.168.100.3 255.255.255.0
Gateway 192.168.100.3 192.168.100.3 255.255.255.0
It is important to briefly touch upon the underlying network architecture, which can be
a 10Mb (Megabit), 100Mb, 10/100Mb, half-duplex, or a full-duplex connection. The
details of the underlying network architecture are beyond the scope of this document,
but it is sufficient to note that most modern network cards, as well as the Tracelink
device, have the capability to configure themselves for the underlying network through
the Auto-negotiation mechanism. Auto-negotiation is performed as soon as a network
cable is connected to the device, and it sets the operating parameters of the device to
match those of the network.
5.4.2 Connecting Tracelink-to-PC via an Ethernet cable
In order to connect the Tracelink to a PC directly via an Ethernet cable, you need to
use what is known as a cross-over cable. A cross-over cable, which is not provided by
P&E, is normally used to connect two similar devices such as a PC to a PC, or a Hub
to a Hub. It is a cable that has its receive and transmit wires crossed over so that the
similar devices can effectively communicate with one another.
With this configuration, it is still important to assign IP numbers to both the PC and the
Tracelink device. Although at first glance it may not seem necessary to assign a
Gateway address in this configuration, the Tracelink was designed to operate on a
network of more than two computers, and therefore it needs to be programmed with a
Gateway address.