Difference Between Inching, Interlock and Self-Locking in RF Decoding

In order to meet the needs of different applications, the output modes of hardware decoding and receiving circuit are usually divided into Inching (M), Interlocking (L), and Self-locking (T). For a long time, many friends can't make the difference between them. Now let's share the differences among the three.

As we may know, wireless RF transceiver module should be used in pairs, encoding/decoding method, as well as the encoding/decoding chips should also match. Decoding can be divided into hardware decoding and software decoding. Hardware decoding IC is divided into three types: Inching, Interlocking and Self-locking.

1.  Inching (M) is also known as momentary control, usually refers to receiving and decoding IC 2272-M4, which is instantaneous high-level output. For example, press the key of the remote control, and the receiver will act once. If the key is not pressed, the receiver will not act. If you press the A key of the remote control, the A key acts, if you do not press, the action stop; press the remote-control B key, B key acts, if you do not press, the B key stops, and so on. It is widely used in the field of garage door and window control.

2.  The Interlocking (L) in wireless remote control receiving and decoding refers to 2272-L4. The simple working mode is as follows: press remote control A key, A key acts, until pressing remote control B key, A key disconnects, B key acts, and so on. Interlocking also known as continuous high-level output, that is, press A key to start, press B key to stop. It is commonly used in various wireless remote-control switches in industrial control.

3.  Self-locking (T) generally refers to 2272-T4, that is, press the same key to open and then press the same key to close. Each key can realize the function of opening and closing independently. It is commonly used in all kinds of light switch.

Simply speaking, Inching (M) is equivalent to light touch switch, Interlock is equivalent to gear switch of fan, and Self-locking is equivalent to lighting switch.

Here are the detailed description of these three modes:

1.  Inching (M): the output level of the data pin is instantaneous and corresponding to whether the transmitter transmits or not. When there is remote control signal, the data pin is high level, and when the remote-control signal disappears, the data pin immediately returns to the low level. (If you press and hold on for a long time, the signal may change into a discontinuous pulse state.)

2.  Interlocking (L): if any channel receives the signal, it can keep the corresponding high-level state all the time, and the data from any other channel will return to the original state, that is, monostable state. The four-channel interlock can only be connected to one channel.

3.  Self-locking (T): The data pin of the self-locking output can realize the trigger flip operation logic. As long as the data is successfully received, it can keep the corresponding level state until the next remote-control data changes. The self-locking four channels are independent of each other and can be remotely controlled at the same time.

For remote control, Interlocking mode is recommended. Since it is easy to miss control, if we use Inching or Self-locking mode for a long-distance control.

As a member of the CLAA, and a third party design office (of TI, Silicon Labs, Semtech), DreamLNK is specialized in radio frequency field for almost 8 years. We can provide you various RF modules and one-stop IoT solutions, including 433/868/915MHz RF modules, 2.4G RF Modules, Antennas, Remote Controls, and customized wireless RF solutions. 

According to the requirement, DreamLNK have developed some special demo board base on our ASK Series Switching Control RF Receiver Modules. If you have any question, please feel free to let us know!