Basic Operation for 4 Channel Remote Control Module with relays:
Operating Voltage: 12V DC.

Each channel's relay has three pins for connection
Relay 1
1,2 = NC
2,3 = NO

Relay 2
4,5 = NC
5,6 = NO

Relay 3
7,8 = NC
8,9 = NO

Relay 4
10,11 = NC
11,12 = NO

Encode/Decode:
On receiver board there is a Decoding IC chip, 2272M4, and inside the remote control there is an Encoding IC Chip, 2262M4. This set of IC Chips can be used to encode your remote signals so if more than one remote system are placed close together, they won't interfere each other. You only need to do little soldering work on Pin #1 through Pin #8 of both chips to bring out the Encode/Decode function of your remote system. Connection on both IC Chips MUST match otherwise the remote and the receiver module can not talk to each other. There are {3 to the power 8} = 6561 different combinations for encoding/decoding, isn't it cool?
On the back of the board there should be labels like:
" L" -------- Stands for Low digital state.
" H" ------- Stands for High digital state.
" 1" -------- Indicates this is Pin #1.
" 8" -------- Indicates this is Pin #8.
Just in case there aren’t any labels printed on the PCB board, you still can easily figure out the “L” and “H” states yourself: After power is hooked up to the system, use a Voltmeter to measure the contacts on both sides of the column of eight pins. Voltage level on each side should be consistence. If one side is “H”, the other side should be “L”.
To figure out Pin #1, look at the front of 2272 or 2262 IC Chip. Pin #1 is the first pin on the left side of the dent.
You don't have to connect all eight pins to High or Low, even only one pin to H or L will do the encoding/decoding.