TDM2312 4-Channel Relay Module with SMS Controlled via 4G

Input Voltage: 11–13V (can custom up to 48V)
Output: 4 relay channels with COM, NC, NO terminals
Relay Max Current:

• 10A at 250VAC
• 8A at 250VDC

Optional Waterproof Enclosure (not included):

• Waterproof Plastic Box 100x68x50mm with Mounting Tabs and Clear Lid
• Or: Waterproof Plastic Box 100x68x50mm with Mounting Tabs

📖 User Guide

Power Setup & Initialization:

• Supply 12V power (make sure to disconnect the programming circuit).
• Confirm the onboard LED is lit.
• Check the SIM module LED is blinking. If not:
  • Measure voltage at VCC-GND pins.
  • Ensure 4V is present at capacitor C7 on the board.
• Wait 10–15 seconds. If the onboard LED blinks slowly, the module is successfully connected.
• Use SMS command set to control relays.

A. Status Check

Send an SMS to the module’s phone number with the following syntax:

Command: A Response Example: Relay: 1 OFF 2 ON 3 ON 4 OFF

B. Relay Control (Registered Numbers Only)

Relay Numbers: 1 to 4 (or up to 6 depending on module type) Syntax: #Command##RelayList# Where:

• Command options:
  • B: Turn ON with response
  • b: Turn ON without response
  • T: Turn OFF with response
  • t: Turn OFF without response
• RelayList: List of relay numbers to control

📲 Examples

Example 1: Turn ON relays 1, 2, and 4 with status feedback SMS: B124 Response:

Control OK!
Relay:
1 ON
2 ON
3 OFF
4 ON

Example 2: Turn OFF relay 1 without feedback SMS: t1