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Wireless Technology

Normally, Remote Control is ultimated through RF, IR control, DTMF etc.. Among IR is used for short-range remote control without obstacle, and DTMF is the better solution for the situation in which no electrical power is provided.

RF-Radio Frequency is widely applied in long-range control situations. In most countries, different RF frequency bands are allocated for different applications in law, especially SHF is for remote control application. Here is the rules in the USA:

http://www.arrl.org/FandES/field/regulations/allocate.html#10

In the United States of America, FCC certification is required for all RF remote control product by Federal Communications Commission, in Canada, there is similar law, then In Europe, it is a little difference, normally CE certification is very important.

We apply ASK/OOK & FSK technologies for remote application. Normally ASK(OOK) product is inexpensive, and the receiver units are with wide brand tolerance, is available enough for some universal applications of home and garden. FSK solution receiver unit is with high sensitivity, anti-jam, easy FCC certified and CE certified. In current technology level, according to the FCC requirements, ASK is for the application with range less than 100m, and FSK can work at range more than 200m. Recent years Rapid Relays has had the range ASK 100m and FSK 250m.

There are Super-regenerative and Super-heterodye types for ASK(OOK) solution. Super-regenerative type apply LC oscillating circuit, built in magnifying exchange, with wide receiving bandwidth ±10MHz. While Super-heterodye type apply SAW crystal oscillation, without easy frequency excursion, with higher sensitivity and reliable performance. Correlative information can be found easily through browsing internet.

Basic conceptions

If you don’t specialize in RF field, and are going to utilize the technology for your project, some basic conceptions must be known by you.

A. Fixed Code, Learning Code & Rolling Code.

They are universal coding modes. Through any one of the modes, receiver unit can work with its correlative transmitting unit separately and won’t be activated by other transmitting units, so that system will work safely.

Fixed Code units apply encoder and decoder i.e. PT2260, PT2262/PT2272, PT2294, SC2262/SC2272, are coded through solder pads, DIP switches or Jumpers etc., it is simple to encode/decode the matching units. There are 6561 combinations for 8-bit chip. Here is a reference on how to code 8-bit chip units:

 

Learning Code units come with more than 1,000,000 combinations, are far more secure than Fixed Code pair. And rolling code pair comes with several millions of combination, and the code changing continuously automatically all the time, is the most secure mode. Then more secure and more expensive.

The matching methods of the both are almost the same, normally there is switch built in the receiver unit, people can operate the switch and the button of transmitter to have them matchable with each other. Following is A example on how to learn Codes of learning code receiver with relay (Model No.: RR1LN):

Turn on supply power, learning indicator blinks, push learning button, learning indicator LED is turned on, then press button of transmitter within 6 seconds, the learning indicator LED blinks twice, learning succeed.

The same steps for the second receiver and the second button of transmitter.

How to clear codes of the receiver:

Keeping pushing learning button for 6 seconds or more, learning indicator LED will be turned on, codes are cleared.

B. Oscillating Resistances

The oscillating resistances of transmitting unit and receiver unit must be matchable each other, otherwise there is not ideal communication effect, the remote range will be shortened and the reliability will be lowered. Following are some matching pairs:

PT2262 PT2260 SC2260 SC2262/PT2264/CS5211 PT2272/SC2272/CS5212
1.2M - 3.3M 1.2M 200K
1.5M - 3.9M 1.5M 270K
2.2M - 5.1M 2.2M 390K
3.3M - 9.1M 3.3M 680K
4.7M 1.2 12M 4.7M 820K

C. Output Mode

Normally there are 3 types of output mode with the relay receiver-MOMENTARY, LATCH, TOGGLE, and 2 types with receiver module with decoder-MOMENTARY and LATCH, they are available for different application. The types lie on the decoders.

When the transmitting unit is a button transmitter, the Modes of the receiver unit work as following:

Momentary: Press->On, Release->Off.
Latch: Press->On, Press others->Off.
Toggle: Press->On, Press Again->Off.


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