Features:
Not Include the RS485 TO USB Module
This document describes the specification of the PZEM-016 AC communication module,
the 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
RS485 interface
PZEM-016: Measuring Range 100A (external transformer)
1. Function description
1.1 Voltage
1.1.1 Measuring range:80 ~ 260V
1.1.2 Resolution: 0.1V
1.1.3 Measurement accuracy: 0.5%
1.2 Current
1.2.1 Measuring range: 0 ~ 100A(PZEM-016)
1.2.2 Starting measure current: 0.02A(PZEM-016)
1.2.3 Resolution: 0.001A
1.2.4 Measurement accuracy: 0.5%
1.3 Active power
1.3.1 Measuring range: 0 ~ 23kW(PZEM-016)
1.3.2 Starting measure power: 0.4W
1.3.3 Resolution: 0.1W
1.3.4 Display format:
< 1000W, it display one decimal, such as: 999.9W
1000W, it display only integer, such as: 1000W
1.3.5 Measurement accuracy: 0.5%
1.4 Power factor
1.4.1 Measuring range: 0.00 ~ 1.00
1.4.2 Resolution: 0.01
1.4.3 Measurement accuracy: 1%
1.5 Frequency
1.5.1 Measuring range: 45Hz ~ 65Hz
1.5.2 Resolution: 0.1Hz
1.5.3 Measurement accuracy: 0.5%
1.6 Active energy
1.6.1 Measuring range: 0 ~ 9999.99kWh
1.6.2 Resolution: 1Wh
1.6.3 Measurement accuracy: 0.5%
1.6.4 Display format:
< 10kWh, the display unit is Wh(1kWh=1000Wh), such as: 9999Wh
10kWh, the display unit is kWh, such as: 9999.99kWh
1.6.5 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 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
The command format of the master reads the measurement result is(total of 8 bytes):
Slave Address + 0x04 + Register Address High Byte + Register Address Low Byte + Number
of Registers High Byte + Number of Registers Low Byte + CRC Check High Byte + CRC Check
Low Byte.
The command format of the reply from the slave is divided into two kinds:
Correct Reply: Slave Address + 0x04 + Number of Bytes + Register 1 Data High Byte +
Register 1 Data Low Byte + ... + CRC Check High Byte + CRC Check Low Byte
Error Reply: Slave address + 0x84 + Abnormal code + CRC check high byte + CRC check
low byte
Abnormal code analyzed as following (the same below)
| Register address | Description | Resolution |
| 0x000 | Voltage value | 1LSB correspond to 0.1V |
| 0x001 | Current value high 16 bits | 1LSB correspond to 0.001A |
| 0x002 | Current value low 16 bits |
| 0x003 | Power value high 16 bits | 1LSB correspond to 0.1W |
| 0x004 | Power value low 16 bits |
| 0x005 | Energy value High 16 bits | 1LSB correspond to 1Wh |
| 0x006 | Energy value low 16 bits |
| 0x007 | Frequency value | 1LSB correspond to 0.1Hz |
| 0x008 | Power factor value | 1LSB correspond to 0.01 |
| 0x009 | Alarm status | 0xFFFF is alarm
0x0000 is not alarm |
2.5 Reset energy
The command format of the master to reset the slave's energy is (total 4 bytes):
Slave address + 0x42 + CRC check high byte + CRC check low byte.
Correct reply: slave address + 0x42 + CRC check high byte + CRC check low byte.
Error Reply: Slave address + 0xC2 + Abnormal code + CRC check high byte + CRC check
low byte
2.6 Calibration
The command format of the master to calibrate the slave is (total 6 bytes):
0xF8 + 0x41 + 0x37 + 0x21 + CRC check high byte + CRC check low byte.
Correct reply: 0xF8 + 0x41 + 0x37 + 0x21 + CRC check high byte + CRC check low byte.
Error Reply: 0xF8 + 0xC1 + Abnormal code + CRC check high byte + CRC check low byte.
It should be noted that the calibration takes 3 to 4 seconds, after the master sends the
command, if the calibration is successful, it will take 3 ~ 4 seconds to receive the response from
the slave.
2.7 CRC check
CRC check use 16bits format, occupy two bytes, the generator polynomial is X16 + X15 +
X2 +1, the polynomial value used for calculation is 0xA001.
The value of the CRC check is a frame data divide all results of checking all the bytes except
