MODBUS CRC
: To maintain data integrity. MODBUS has implemented CRC which is
appended to the message. The receiver uses this checksum to detect
any error in the query. Kindly refer to official MODBUS document for CRC
calculation.
MODBUS Query
: Below is MODBUS query to read active energy.
MODBUS Response
:
Note that always validate the response like slave ID, CRC, Function code etc
before extracting the data bytes. kindly refer to official modbus document
for the same.
Extracting Data from Response:
Arrange data bytes in order ABCD to get the
data. Enersol modbus registers are in float &
use IEEE 754 representation for float value.As per
IEEE 754 46BA2800 (in hexadecimal) is float
representation of 23.8
Kwh
.
Page 27
Q: What is Line terminal?
A: Signal wire impedance mis-match causes reflections in the signal wire. To avoid
this, Enersol recommends to use 100E / 1Watt resistace at ends of the
communication bus. But it is optional, use this when required.
1
1
1
1
1
2
2
2
2
2
3
3
3
3
3
4
4
4
4
4
5
5
5
5
5
6
6
6
6
6
7
7
7
7
7
8
8
8
8
8
9
9
9
9
9
10
10
10
10
10
11
11
11
11
11
12
12
12
12
12
13
13
13
13
13
14
14
14
14
14
15
15
15
15
15
16
16
16
16
16
17
17
17
17
17
18
18
18
18
18
Voltage inputs 80 = 480VAC LL
Voltage inputs 80 = 480VAC LL
Voltage inputs 80 = 480VAC LL
Voltage inputs 80 = 480VAC LL
Voltage inputs 80 = 480VAC LL
Current Input: 50mA to 60A
Current Input: 50mA to 60A
Current Input: 50mA to 60A
Current Input: 50mA to 60A
Current Input: 50mA to 60A
Ph N
Ph N
Ph N
Ph N
Ph N
Aux. Sup.
90-300V, 2VA
Aux. Sup.
90-300V, 2VA
Aux. Sup.
90-300V, 2VA
Aux. Sup.
90-300V, 2VA
Aux. Sup.
90-300V, 2VA
RS485
RS485
RS485
RS485
RS485
DANGER
DANGER
DANGER
DANGER
DANGER
Turn off power before working
Turn off power before working
Turn off power before working
Turn off power before working
Turn off power before working
R CT
R CT
R CT
R CT
R CT
Y CT
Y CT
Y CT
Y CT
Y CT
B CT
B CT
B CT
B CT
B CT
RS485
RS485
RS485
RS485
RS485
V1 V2 V3 Vn
V1 V2 V3 Vn
V1 V2 V3 Vn
V1 V2 V3 Vn
V1 V2 V3 Vn
+
+
+
+
+
-
-
-
-
-
Master
Device
100E / 1 W
100E / 1 W
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Byte 8
Slave ID
Function
Code
No. of
bytes
received
Data
Byte C
Data
Byte D
Data
Byte A
Data
Byte B
Least
significant
byte of
MODBUS
CRC
Most
Significant
byte of
MODBUS
CRC
01
03
04
28
00
46
BA
40
40
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
Slave ID
Function
Code
Most
significan
t byte of
“Start
Address
Least
significant
byte of
“Start
Address”
Most
significant
byte of
“No of
registers
required”
Least
significant
“No of
registers
required”
Least
significant
byte of
MODBUS
CRC
Most
Significan
t byte of
MODBUS
CRC
01
03
0F
3B
00
02
B6
D2
LCD
Series
ENERSOL
MFLR09
PROG
COM
Tot: 1.80KW
00000023.8 KWh
