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TDM2507-Power Metter Module

User Manual 

Overview 

This document describes the specification of the TDM2507 AC Power Metter Module. 
This module is mainly used for measuring AC voltage, current, active power, frequency, power factor and active energy, the module is without display function, the data is read through the TTL interface. 

  • Variant selection:
    TDM2507-1-10A: Measuring Range 10A (Built-in Shunt 1mOhm) 
  • TDM2507-2-10A: Range 10A (external CT) 
  • TDM2507-3-100A: Range 100A (external CT) 

 

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Note: the module does not come with a plastic case, if you want to have plastic case, please order from this link

Function description 


Voltage Measuring range:80～260V 
Resolution: 0.1V 
Measurement accuracy: 0.5% 
1.2 Current Measuring range: 0～10A(TDM2507-3-10A); 0～100A(TDM2507-3) 
Starting measure current: 0.01A(TDM2507-1-10A); 0.02A(TDM2507-3-10A) 
Resolution: 0.001A 
Measurement accuracy: 0.5% 
1.3 Active power Measuring range: 0～2.3kW( TDM2507-1-10A-10A);

0～23kW(TDM2507-3 -100A) 
Starting measure power: 0.4W  
Resolution: 0.1W  
Display format:  
＜1000W, it display one decimal, such as: 999.9W 
≥1000W, it display only integer, such as: 1000W 
Measurement accuracy: 0.5% 
1.4 Power factor  
Measuring range: 0.00～1.00 
Resolution: 0.01  
Measurement accuracy: 1% 
1.5 Frequency 
Measuring range: 45Hz～65Hz  
Resolution: 0.1Hz  
Measurement accuracy: 0.5% 
1.6 Active energy 
Measuring range: 0～9999.99kWh  
Resolution: 1Wh  
Measurement accuracy: 0.5% 
Display format:  
＜10kWh, the display unit is Wh(1kWh=1000Wh), such as: 9999Wh  
≥10kWh, the display unit is kWh, such as: 9999.99kWh  
Reset energy: use software to reset. 
1.7 Over power alarm 
Active power threshold can be set, when the measured active power exceeds the threshold, it 
can alarm 
1.8 Communication interface  
RS485 interface。 

2 Communication protocol  

2.1 Physical layer protocol 
Physical layer use UART to RS485 communication interface 
Baud rate is 9600, 8 data bits, 1 stop bit, no parity 
2.2 Application layer protocol 
The application layer use the Modbus-RTU protocol to communicate. At present, it only 
supports function codes such as 0x03 (Read Holding Register), 0x04 (Read Input Register), 0x06 
(Write Single Register), 0x41 (Calibration), 0x42 (Reset energy).etc. 
0x41 function code is only for internal use (address can be only 0xF8), used for factory 
calibration and return to factory maintenance occasions, after the function code to increase 16-bit 
password, the default password is 0x3721 
The address range of the slave is 0x01 ~ 0xF7. The address 0x00 is used as the broadcast 
address, the slave does not need to reply the master. The address 0xF8 is used as the general 
address, this address can be only used in single-slave environment and can be used for calibration 
etc.operation. 
2.3  Read the measurement result

Functional block diagram

A. With direct current measure via shunt resistor 
B. With CT current sense (default 10A)

4. Wiring Diagram

Addition Note: 

  • The TTL interface of this module is a passive interface, it requires external 5V or 3V3 power supply, which means, when communicating, all four ports must be connected (5V, RX, TX, GND) with external MCU/usb serial, otherwise it cannot communicate.

  • Becarefull to select the right version and read the wiring instructions carefully

Programing Example:

Test with ESP32-C3:  bl0942_esp32c3.zipLink.....
ESP32C3 Pin----- TDM2507

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