Infrared Transmitter Wiring

[slychiu]

Please note that the wiring from Comfort outputs to IR transmitters should be using twisted pairs (CAT 5 recommended)
Never use Alarm cables, which are untwisted, and never run several IR signals from several outputs within the same cable as it is possible for IR signals on one cable to be induced to a cable which is physically next to it. This may cause the IR signal to affect the device connected to the adjacent cable IF the IR transmitter is placed very close to the IR receiver of the device
Keep individual IR cables away from each other by at leat 25 mm, DO NOT run them side by side or within the same CAT 5 cable
If the IR Trsnsmitter is placed directly in contact wth the IR Reeceiver, the chances of a stray IR signal from another output causing a false IR signal to be transmitted is greater. In such situations, connect a 12V test lamp (available from Cytech) across the adjacent output which also sends an IR signal.

[DR]

I control IR signal for 20 HVAC and 5 audio systems.

Should cat.5e STP  be chosen, since it\'s better than UTP for interference reason ? and is it good using 3-4 STP cables in one conduit?

Thank you. 

 

[slychiu]

Certainly STP is preferrable to UTP, I would not say it is required. We have encountered interference when several IR signals are sent using different pairs within the same UTP cable but not if different cables entirely are used for the IR signals. It should not be a problem to use cables within the same conduit. We certainly could not expect people to use separate conduits!

The problem we encounter when adjacent pairs are used within the same cable is only if the IR transmitters are very close to the IR receivers so that stray or very weak signals could activate the IR receiver eg if you use a stick-on IR emitter right on the AV receiver. If you rae tranmistting to the AV from a distance then you would not have that problem

[adlim]

Another point to note would be the type of IR codes to be sent out. If all the various devices to be controlled are each using unique IR codes, then you would not need to worry about interference as the induced signal would not be able to control other devices.

[DR]

How long max distance IR wiring using UTP (24AWG) cable from one device to comfort panel/IR modul?

Some A/V systems have RS232, but as RS232 cable is limited at 15m (good signal), is it right? So I change to IR.

Have you ever found interference trouble using some IR/UTP cables for air conditioning & A/V in one conduit ( one-4pair cable each device) since a/c is more generate noise than a/v?

Regards.

[adlim]

Yes, RS232 has a much more restrictive length. If you wish to use RS232, I would gather you would be using a UCM/UCX connected to the A/V system. However, the distance between Comfort and the UCM/UCX can be much longer, allowing you to overcome the distance problem.

[ident]

A/C and AV IR cables sharing the same conduit should be no problem as the signals are different. Even if there is interference from one to the other, the A/C signal sent to the AV equipment would cause no harm
Moreover you use separate cables so no interference at all