Protocol; Example Of Modbus Query; Modbus Map - Circutor SVGm IP54 Manual De Instrucciones

SVGm IP54

8.2.- PROTOCOL

In the Modbus protocol, the SVGm IP54 uses the RTU (Remote Terminal Unit) mode.
The Modbus functions implemented in the device are as follows:
Functions 03 and 04: Reading of n Words (2 bytes).

8.2.1.- EXAMPLE OF MODBUS QUERY

Query: Value of the Load current of L1
Address: 0A, Peripheral number: 10 in decimal.
Function: 03, Read function.
Initial Register: 92, register from which to start reading.
No. of registers: 0002, number of registers to be read.
CRC: xxxx, CRC character.
Response:
Address
0 A
Address: 0A, Responding peripheral number: 10 in decimal.
Function: 03, Read function.
No. of bytes: 04, No. of bytes received.
Register: 000000FA,
CRC: xxxx, CRC character.

8.2.2.- MODBUS MAP

All Modbus map variables are in hexadecimal format.
For these variables, Functions 03 and 04 are implemented.
8.2.2.1.- Load Measurements
Parameter
Current with Load
Active power with Load
Reactive power with Load
Apparent power with Load
cos ɸ with Load
Instruction Manual
Address Function
register
0A 03
Function No. of Bytes
03 04
value of load current L1, with 1 decimal: 0xFA = 25.0 A
Table 14: Modbus memory map: Measurements with Load.
L1 L2 L3
93 - 92 95 - 94 97 - 96
AD - AE AF - B0 B1 - B2
B3 - B4 B5 - B6 B7 - B8
B9 - BA BB - BC BD - BE
D1 D2 D3
Initial No. of
CRC
registers
92 0002 xxxx
Register no. 1 Register no. 2
0000 00FA
LN
99 - 98 [Hi] + [Low] A with 1 decimal
- kW with 2 decimal places and sign.
- kVar with 2 decimal places and sign.
- kVA with 2 decimal places and sign.
-
CRC
xxxx
Units
With 3 decimal
129