NETWORKING CONCEPTS

Networking Concepts Assignment

Networking Concepts Assignment

LAN for EasySolution

The Easy Solutions Services organization was commissioned to provide the needed product expertise and also solve the integration challenges. Here we are going to design a working LAN for the company consisting of 25 terminals and 3 Servers.

Remote control capabilities through TCP/IP via an Ethernet interfaces are these days usually implemented in every test and measurement device due to the widespread presence of this kind of networking technology. It provides for easy access and routing of signals through any local site and even around the world. Earlier serial interfaces of RS232 type have been the default and are still in legacy use. To utilize this new technology even in cases when only an RS232 interface is present a terminal server can be used for interfacing.

Hard- and Software Requirements

Hardware Requirements

The application note discusses the required settings for a terminal server from Black Box® Corporation using instruments of type DVRM, DVMD and EFA. The model that is described in the application note is the 4 port desktop version #41874. Other models, like the 2 port desktop #41874 or rack mount versions (#40871 for 8 ports and #40870 for 16 ports) are working in the same manner.

The 8-port (#37688) and 16-port (#37687) desktop versions will be identical regarding software set-up, however they require different cable connections, as they have 25 pin DB25 connector plugs for the serial interfaces (DB9 to DB25 null modem cables).

Terminal servers from different manufacturers can be used, but will require different steps for set-up. Please refer to the manufacturer's manual for detailed instructions in any case. All notes regarding set-up of the application software packages (EFA Scan, Realtime Monitor and Stream Explorer) and the instruments in section 5 are usually valid no matter which terminal server is used.

Software Requirements

The application software used for remote control through a terminal server needs to have a method of sending and receiving the instruments commands directly to and from an Ethernet port with a given TCP/IP address and a port number instead of the local RS232 port. All three software packages discussed in this application note (Realtime Monitor, Stream Explorer DVMD-B1 and EFA Scan) have that basic capability.

If the application software does not offer this direct addressing capability (for example Pcx2disc.exe), separate server software is needed to emulate a local COM port by running as a background task. In that case the application software will see the remote serial interfaces identical to local interfaces, one of which can be chosen in the set-up as the port of choice.

The server software then converts all remote commands to and from the application software into the TCP/IP channel and communicates with the terminal server at the other end. This application note does not describe the latter type of communication through a software server, but rather the direct addressing of the terminal server's Ethernet (TCP/IP) address by the application software.

Connecting the Computer and the Instrument(s)

The discussed terminal servers from Black Box® have RJ45 plugs for the serial ...