Uni-t Ute9811+ Smart Digital Power Meter User Manual (+ PDF)

UNI-T products are protected by patents (including obtained and
pending) in China and other countries and regions.
UNI-T reserves the right to change specifications and prices. The
information provided in this manual supersedes all previous
publications. The information provided in this manual is subject to
change without notice. UNI-T shall not be liable for any errors
that may be contained in this manual. For any incidental or
consequential damages arising out of the use or the information and
deductive functions provided in this manual. No part of this manual
shall be photocopied, reproduced or adapted without the prior
written permission of UNI-T.

Product Certification

UNI-T has certified that the product conforms to China national
product standard and industry product standard as well as
ISO9001:2008 standard and ISO14001:2004 standard. UNI-T will go
further to certificate product to meet the standard of other member
of the international standards organization.

Chapter 1 Modbus Programming

1.1 Modbus

Modbus is a widely used field bus protocol. Multiple slave
machines can easily network with the host through Modbus, the host
computer can be PC or PLC. Modbus has two varieties, which is
Modbus-RTU and ModbusASC. UTE9811+ only supports Modbus-RTU.

1.2 Communication Interface and Setting

The detailed explanation can refer to Chapter 6 Communication
Setting and Chapter 8 Communication Interface of UTE9811+ User’s
Manual.

1.3 Data Format of Communication

During communication, data is return in the format of word (two
bytes). Each returned word with the high byte in the front and low
byte in the behind. If two words continuous return (such as
floating point number number or long integer), then high byte in
the front, the low byte in the behind.

Data Format	Byte Data	Number of Register	Number of Byte	Description
Integer Data	1	2		A return, high byte in the front and low byte in the behind
Long Integer Data	2		4	Return in two words, high byte in the front and low byte in the behind
Floating Point Number Data	2		4	Return in two words, high byte in the front and low byte in the behind

1.4 Interconversion of Word and Float Point

A register in Modbus protocol is 16 bits, that is a word. The
previous section mentioned that floating-point take up two
registers, i.e., two words. After receiving byte data, user needs
to convert a word to a floating-point or a floating-point number to
a word. The following code is good example for interconversion of
word and float point.

/* C program for converting a floating point number to two words */
void FloatToWord(float Data,u16 *Word) {
union {
float Data; unsigned char Byte[4]; }FloatData;
FloatData.Data=Data;
Word[0]=(u16)FloatData.Byte[3]8)&0xFF;
FloatData.Byte[0]=(Word[1])&0xFF;
return FloatData.Data; }

1.5 Modbus-RTU

UTE9811+ only supports Modbus-RTU.

Product Usage Instructions:

The UTE9811+ Smart Digital Power Meter is compatible with
Modbus-RTU protocol. The communication interface and setting can be
found in Chapter 6 Communication Setting and Chapter 8
Communication Interface of the UTE9811+ User’s Manual. During
communication, data is returned in the format of word (two bytes)
with the high byte in the front and low byte in the behind. If two
words are continuously returned (such as floating point number or
long integer), then high byte is in the front and low byte is in
the behind. Users need to convert a word to a floating-point or a
floating-point number to a word using the provided code.

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UTE9811+ Smart Digital Power Meter
Modbus Programming Manual
REV 00 2023.2

Copyright
2023 Uni-Trend Technology (China) Co., Ltd.
Brand Information
UNI-T is the registered trademark of Uni-Trend Technology (China) Co., Ltd.
Software Version
00.00.01 Software upgrade may have some change and add more function, please subscribe UNI-T website to get the new version or contact UNI-T.
Statement
UNI-T products are protected by patents (including obtained and pending) in China and other countries and regions.
UNI-T reserves the right to change specifications and prices. The information provided in this manual supersedes all previous publications. The information provided in this manual is subject to change without notice. UNI-T shall not be liable for any errors that may be contained in this manual. For any incidental or
consequential damages arising out of the use or the information and deductive functions provided in this manual. No part of this manual shall be photocopied, reproduced or adapted without the prior written permission of UNI-T.
Product Certification
UNI-T has certified that the product conforms to China national product standard and industry product standard as well as ISO9001:2008 standard and ISO14001:2004 standard. UNI-T will go further to certificate product to meet the standard of other member of the international standards organization.
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Chapter 1 Modbus Progamming

1.1 Modbus
Modbus is a widely used field bus protocol. Multiple slave machines can easily network with the host through Modbus, the host computer can be PC or PLC. Modbus has two varieties, which is Modbus-RTU and ModbusASC. UTE9811+ only supports Modbus-RTU.
1.2 Communication Interface and Setting
The detailed explanation can refer to “Chapter 6 Communication Setting” and “Chapter 8 Communication Interface” of UTE9811+ User’s Manual.
1.3 Data Format of Communication
During communication, data is return in the format of word (two bytes) . Each returned word with the high byte in the front and low byte in the behind. If two words continuous return (such as floating point number number or long integer), then high byte in the front, the low byte in the behind.

Data Format Byte Data
Integer Data
Long Integer Data Floating Point Number Data

Number of Register 1 2

Number of Byte 1 2
4

Description
A return, high byte in the front and low byte in the behind Return in two words, high byte in the front and low byte in the behind

1.4 Interconversion of Word and Float Point

A register in Modbus protocol is 16 bits, that is a word. The previous section mentioned that floating-point take up two registers, i.e., two words. After receiving byte data, user needs to convert a word to a floating-point or a floating-point number to a word. The following code is good example for interconversion of word and float point.

/* C program for converting a floating point number to two words */ void FloatToWord(float Data,u16 *Word) { union {
float Data; unsigned char Byte[4]; }FloatData; FloatData.Data=Data;

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Word[0]=(u16)FloatData.Byte[3]<<8|FloatData.Byte[2]; Word[1]=(u16)FloatData.Byte[1]<<8|FloatData.Byte[0]; } /* C program for converting two words to a floating point number */ float WordToFloat(const u16 *Word) { union {
float Data; unsigned char Byte[4]; }FloatData; FloatData.Byte[3]=(Word[0]>>8)&0xFF; FloatData.Byte[2]=(Word[0])&0xFF; FloatData.Byte[1]=(Word[1]>>8)&0xFF; FloatData.Byte[0]=(Word[1])&0xFF; return FloatData.Data; }
1.5 Modbus-RTU
1.5 1 Function code 03Hread multiple words
This command can read at least one word. The following example issues a read command from the master station to slave station 1, reading two consecutive words that start from address 0096H (150) .

Command Message of Master Station

Slave address Function code Position of initial data Data number (calculating in word) CRC(Check Low) CRC(Check High)

01H 03H 00H (high byte) 96H (low byte) 00H 02H
24H (low byte) 27H (high byte)

Respond Message of Slave StationNormal

Slave address

01H

Function code

03H

Data number

04H

( calculating in byte)

Start data address

40H (high byte)

0096H

DDH (low byte)

The second data

1EH (high byte)

address 0097H

B8H (low byte)

CRC(Check Low)

76H (low byte)

CRC(Check High)

1BH (high byte)

Respond Message of Slave StationAbnormal

Slave address

01H

Function code

83H

Error Code

02H

CRC(Check Low)

C0H (low byte)

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CRC(Check High)

F1H (high byte)

1.5.2 Function code 10Hwriting multiple words
This command can write at least one word. The following example issues a write command from the master station to slave station 1, writing data of two words 0003H and 0002H from the start address 0065H(101) . That is write 0003H into address 0065H, write 0002H into address 00066H. The slave replies to the master station when the write is completed.

Command Message of Master Station

Slave address

01H

Function code

10H

Position of initial

00H

data

65H

Data number

00H (high byte)

(calculating in word)

02H (low byte)

Data number

04H

( calculating in

byte)

The first data

00H (high byte)

address

03H (low byte)

The second data

00H (high byte)

address

02H (low byte)

CRC(Check Low)

44 (low byte)

CRC(Check High)

79 (high byte)

Respond Message of Slave StationNormal

Slave address

01H

Function code

10H

Position of initial

00H (high byte)

data

65H (low byte)

Data number

00H (high byte)

(calculating in

02H (low byte)

word)

CRC(Check Low)

51H (low byte)

CRC(Check High)

D7H (high byte)

Respond Message of Slave StationAbnormal

Slave address Function code Error Code CRC(Check Low) CRC(Check High)

01H 90H 02H CDH (low byte) C1H (high byte)

1.5 3 Description of Error Code

Error code parsing for respond message of slave station (abnormal) as shown in the following figure.

Error Code

Name

Description

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Illegal function code The slave machine does not support this function code.

Illegal data address The starting data position or a combination of the starting

data position and the number of transmitted data received

from the machine is not allowed.

Illegal data value

Data received from the machine is not allowed.

1.6 Register List

The data register of UTE9811+ as shown in the following table. *Notes

1.R represents it can be read and supports command 03H. W represents it can be written and supports

command 10H.

2. “Voltage range”, “current range”, “user’s defined input signal frequency” can only be used when set the user’s grade to High. The specific step can refer to section 7.3 user’s grade in UTE9811+ User’s Manaul.

Data Name

Data

Initial Number of

Unit

Read/Write Remarks

Format

Address Register

Product Information

Product information

ASCII

“UNIR
T,UTE9811+ ,012345678,F1.02”

Retain

Parameter Setting

0: normal TRMS (RMS)

1: harmonic distortion (THD%)

Measurement U16
mode

100

2: measured value of harmonic R/W
(THD)

3: crest factor (CF)

4: TRMS harmonic (HARM-RMS)

Voltage range* U16

101

0 (Auto), 1 (75V), 2 (150V), R/W
3 (300V), 4 (600V)

Current range* U16

102

0 (Auto), 1 (0.2A), 2 (1A), R/W
3 (4A),4 (20A)

Update cycle

U16

Average

U16

Data hold

U16

Display

U16

Mute

U16

103

104

105

106

107

0 (0.1s), 1 (0.25s), 2 (0.5s), R/W
3 (1s), 4 (2s), 5 (5s)

0 (the average is turned off), 1 (8

R/W

times), 2 (16 times),

3 (32 times), 4 (64 times)

R/W

0 (forbidden), 1 (enabled)

0 (display PF value), 1 (display R/W
frequency value)

R/W

0 (forbidden), 1 (enabled)

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Upper limit of current alarm
Lower limit of current alarm
Upper limit of power limit
Lower limit of power limit
Alarm delay User’s defined input signal
frequency Measurement
data type

Float Float Float Float Float Float U16

Default setting

U16

Save parameter U16

Voltage value

Float

Current value
Active power Power factor Frequency of
voltage Alarm state of
current
Alarm state of power

Float Float Float Float
U16
U16

Data update U16
count

Voltage CF

Float

108

R/W

110

R/W

112

R/W

114

R/W

116

R/W

118

R/W

120

R/W

Parament Configuration of Instrument

140

141

Measurement Data

150

152

154

156

158

160

161

162

Measurement Data of Crest Factor

190

0.000~40.000 When the upper limit and the lower limit is set to 0 at the same time, it represents the alarm is forbidden. 0.000~48000.0 When the upper limit and the lower limit is set to 0 at the same time, it represents the alarm is forbidden. 0.0~99.9
0.0 or 40.0~70.00.0 represents this function is disabled.
0: real-time measurement data 1: recently update TRMS data
0 (forbidden), 1 (set the parameter to the default value) 0 (forbidden), 1 (save the parameter into system storage for next use)
The numerical value is related to the measurement model. The numerical value is related to the measurement model.
0 (alarm forbidden), 1 (wait for connect to the load), 2 (testing), 3 (the result is normal), 4 (the result is low), 5 (the result is high) The latest measurements are available when changes in this data are detected.
The ratio of voltage crest value and RMS voltage.
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Current CF

Float

192

Measurement Data of Harmonic

Total voltage

Float

200

distortion factor

Measured value

of total voltage Float

202

distortion factor

Total current

Float

204

distortion factor

Measured value

of total current Float

206

distortion factor

Voltage

distortion factor Float

208

100

of 1~50 times

Measured

voltage value of Float

308

100

1~50 times

Current

distortion factor Float

408

100

of 1~50 times

Measured

current value of Float

508

100

1~50 times

Total RMS

Float

608

voltage

Total RMS

Float

610

current

Total RMS

Float

612

active power

The ratio of current crest value and RMS current.
Total voltage distortion factor
Measured value of total voltage distortion factor
Total current distortion factor
Measured value of total current distortion factor
Voltage distortion factor of 1~50 times
Measured voltage value of 1~50 times
Current distortion factor of 1~50 times
Measured current value of 1~50 times
Total RMS voltage
Total RMS current
Total RMS active power

The Meaning of Special Data

Floating point number 9.91E+37 in measurement data, which represents invalid data, window displays “—-“; Floating point number 9.9E+37 in measurement data, which represents the data is overrange or overflow, window displays ” –oL-” or “–oF-“.

Appendix 1 CRC Calculation
const unsigned char aucCRCHi[] = { 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,

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0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40 };
const unsigned char aucCRCLo[] = { 0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09, 0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3, 0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A, 0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26, 0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F, 0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5, 0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C, 0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89,

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0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C, 0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80, 0x40 };

unsigned short usMBCRC16( unsigned char * pucFrame, unsigned short usLen )

{

unsigned char ucCRCHi = 0xFF;

unsigned char ucCRCLo = 0xFF;

int

iIndex;

while( usLen– ) {
iIndex = ucCRCLo ^ *( pucFrame++ ); ucCRCLo = ( unsigned char)( ucCRCHi ^ aucCRCHi[iIndex] ); ucCRCHi = aucCRCLo[iIndex]; } return ( unsigned short )( ucCRCHi << 8 | ucCRCLo ); }

unsigned char SendBuf[30]; void main(void) {
unsigned short CRC; unsigned short SendLen; SendLen = 0;

SendBuf[SendLen++] = 0x01; SendBuf[SendLen++] = 0x03; SendBuf[SendLen++] = 0x00; SendBuf[SendLen++] = 0x96; SendBuf[SendLen++] = 0x00; SendBuf[SendLen++] = 0x02; CRC = usMBCRC16(SendBuf,SendLen); /*start to calculating CRC */ SendBuf[SendLen++] = CRC&0xFF; /* CRC low byte */ SendBuf[SendLen++] = (CRC>>8)&0xFF; /* CRC high byte */ }

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