I'm new in RF systems and currently want to create a silent alarm security system with a Tuya 4CH relay and 4 controllers of the same brand. Each controller button A will be linked to a different relays channels. My question is, these controllers have an ID system or not. I don't want that pressing the A button in one of the controllers ends triggering all the channels in the relay.

 

Welcome to AAC.

First—these devices are not suitable for health and safety use. They operate in a band that is subject to a lot of interference and a nearby rogue transmitter (intentional or more likely unintentional) could easily prevent operation.

Additionally, the Tuya board is not designed for the application which means it will lack the reliability the application demands.

Second—the answer to your question brings up other difficulties. Yes, each EV1527 chip has an OTP (One Time Programmable) 20-bit address. This address will come programmed by the manufacturer of the transmitter it is used it. What they choose—all the same or each unique—is a problem for you either way.

The EV1527 is intended for use with learning receivers. That is, the receiver is put into learning mode (usually with a button on the PCB) and the transmitter you wish to use with it is operated nearby. This pairs the TX-RX pair with one 20-bit code.

So it turns out the problem is not the transmitter per se, but the receiver. It is extremely unlikely you will find one with four independent decoders allowing four unique fobs to be paired.

In the end, this is an inadvisable approach to your project and suffers from several potentially tragic flaws:

1. The 433MHz band is full of cheap transmitters, many used for inappropriate applications proscribed by regulation that include long transmissions that could easily block your use when you need it.
   
   
2. The devices you propose to use are not intended to be reliable, which your application demands. Everything from silent failure to a dead battery (without warning) could prevent operation when it is needed.
   
   
3. If you intend to use any of the network/cloud capabilities of the Tuya device, multiplied the unreliability is increased by an order of magnitude. And, the latency of this facility is unpredictable and failure for many reasons is very possible.
   

The alternative is to use devices designed for your application. For example, this Bosch RADION pendant is designed for panic alarm use. It uses a secure, supervised link, intended to ensure activation is possible when it is needed, and It has only one button so the user (while under stress) can't press the wrong one.

Unfortunately, the receiver these will be much more costly than your proposed parts, and the receiver is intended for use with a real alarm panel—but that's probably the only reasonable option. It's not that you couldn't eventually assemble something reliable—but the parts you would use, the prototypes, and the time invested would total to at least as much as, if not more than, the commercial solution which will be reliable and refined.

Panic alarms are health and safety items and it makes little sense to create a false sense of security by providing something that has a very real chance of failing completely when it is needed. I would strongly encourage you to look for an affordable commercial solution either in the form of parts you assemble or working with a commercial installer with a good reputation and a lot of experience.

Good luck with your project.

 

A wireless security system is very easy to disable. All it takes is a much more powerful signal source to put the receiver into a heavy overload mode where it can not hear any of the sending units. AND just a few watts can easily do that. Not enough power to attract attention, really. And then when the time to leave arrives, switch off the transmitter and it leaves no evidence for how the receiver was disabled.