TDM2507-Power Metter Module

User Manual 

Overview 

TDM2507 is a built-in clock calibration-free energy metering module, which is suitable for single-phase multi
function electricity meters, smart sockets, smart home appliances and other applications, with more cost
efficient solution.

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)

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

Function description 

range:80～260V range:0～9999.99kWh 1Wh
format: thedisplayunitisWh(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。 

Voltage Measuringmeasuremnt	10-300Vac	Resolution:
Power Acccurracy	Less than 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% 1.5error Frequencyin Measuring range: 45Hz～65Hz   Resolution: 0.1Hz   Measurement accuracy: 0.5%  1.6 Activeactive energy measurement over a dynamic range of 4000:1	Measuring
Current RMS range ( Onboard shunt version)	(10mA ~ 30A) @ 1mOhm	TDM2507-1-10A
Current RMS range ( External CT 10A)	0-10A Using CT DL-CT08CL6-1000 10A	TDM2507-2-10A
Current RMS range ( External CT 100A)	0-100A CT DL-CT08CHL18-2000	TDM2507-3-100A
Resolution	Resolution:
Active Energy Measurement accuracy:Error	0.5%	Display
＜10kWh,

2 Communication protocol  

2.1 Physical layer protocol 

Physical layer use UARTUART.

to RS485 communication interface 

Baud rate is 96004800, 8 data bits, 1 stop bit, no parity 
2.2

Application

Support layerpacket protocolreading

Baud Rate Configuration: 
The

application

BL0942 layercan useconfigurate theBaud Modbus-RTURate protocolby register MODE [9:8] and SCLK_BPS pin. But we recommend to communicate.keep Atbaurate present,at it4800bps onlyto
supportsadvoid functionnoise codesimmunity.

such

as

Refer 0x03techincal (Read Holding Register), 0x04 (Read Input Register), 0x06 
(Write Single Register), 0x41 (Calibration), 0x42 (Reset energy).etc. 
0x41 function code is onlydatasheet for internalmore usedetails: (addressBL0942 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

Datasheet

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.zip
ESP32C3 Pin----- TDM2507

      Pin 4 ----- TX

      Pin 5 ----- RX

      GND ----- GND

      3V3 ----- VCC