Two Ports are Better Than One

07/15/2016

Blog post by SimGHOSTS President Scott Crawford

Two Ports are Better Than One

Cate 5e and now Cat 6 terminal ports (RJ45) are ubiquitous within the healthcare simulation environment, as well as in every other building or industry that uses a computer. Most people view these 8 conductor ports and jacks as a convenient, secure, and fast connection to an internal network or the World Wide Web. These simple cables and terminals are useful for ever so much more than this, but it requires users to think outside of the box.

The eight conductors that are required for Gigabit connection speeds (1000 kbits/second) can be divided. Using only four of these eight wires will still give you a viable network connection at 100 kbits/second, fast enough for all but the most data heavy transmissions. Both of these connections still require a network interface card; and usually a switch, gateway or server to be useful for connection between devices. But what if these cables were thought of as just wires, how else could they be put to use?

 

A patch panel was used in the past in the telephone industry to physically transfer an incoming call from one line to another at a telephone switch board. This same concept can allow a signal to be easily directed from one port to another in a simulation center. We ran an XLR audio input and output from each control station to a central patch panel in our server room. This system allows easy expansion of analog audio connections for communication from every simulation room to every control station in our center even if we are viewing over a network IP video stream with a small delay. A Cat 6 wire can be terminated into the back of a rack and made into an easily accessible patch panel in the same manner.

If two Cat 6 ports are paired together in location and termination 16 total conductors are available. As it so happens this type of paired cable run allows for some unique signals to be transmitted. HDMI cables known for transmitting high definition video and audio signals together on the same wire have a significant length limitation of 50ft. Any signal that needs to be transmitted further than this must be amplified or send over a specialty cable. Some specific cables using RedMere technology can send a signal a further distance, but the source and output must be pre-defined. Special adapter cables can be used to send an HDMI signal using a paired Cat 6 cable up to 100ft. These cables are still subject to a input and output source distinction, but as the primary cable distance is in the wall, the adapter box can be more easily moved should the source and display move. This type of adapter can expand the possibilities of video transmission using existing infrastructure.

Audio signals can also been designed to use a similar cable structure. Although often lacking the ideal shielding in a long cable run, companies like TOA planned on using this type of paired Cat 6 cabling for transmission of audio for a paging system. Our center has used a TOA multi-zone paging system to provide overhead announcements to individual simulation rooms, hallways, or lecture rooms. Because the selection of zone and audio are transmitted using a paired Cat-6 cable, we were able to use a paired Cat-6 patch system to allow the microphone to move between control rooms if necessary for these global announcements.

One more use of Cat 6 cables is for USB transmission. USB cables are also subject to length limitations of ~15 ft, but if you need to connect a pulse oximeter from the control computer to a plug under the bed, to avoid tripping learners, a USB extender is available from many vendors such as Monoprice that will send the signal using a RJ45 8-conductor terminal up to 150 ft.