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

8.2.- PROTOCOL

In the Modbus protocol, the AFQm 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: 0A, Responding peripheral number: 10 in decimal.
Function: 03, Read function.
No. of bytes: 04, No. of bytes received.
Register:
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
Current THD with Load
154
Address Function
0A 03
Address Function
0 A 03
000000FA,
value of load current L1, with 1 decimal: 0xFA = 25.0 A
Table 17: Modbus memory map: Measurements with Load (Table 1).
L1 L2
93 - 92 95 - 94
AD - AE AF - B0
B3 - B4 B5 - B6
B9 - BA BB - BC
D1 D2
8C 8D
Initial No. of
register registers
92 0002
No. of Bytes Register no. 1
04 0000
L3 LN
97 - 96 99 - 98
B1 - B2 -
B7 - B8 -
BD - BE -
D3 -
8E -
CRC
xxxx
Register no. 2 CRC
00FA xxxx
Units
[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.
With 3 decimal
% with 1 decimal
Instruction Manual
AFQm IP54