HBM Anybus CompactCom Modbus TCP Manuel D'instructions page 5

Anybus, Modbus TCP
2 Parameter documentation
2.1 Parameters for cyclic data
Use the Modbus function "Read Input Register (0x04)" to access cyclic
indicator data. According to the mode specifications, you can read out a
maximum of five values of 16 bits each (quantity = 5); for addressing,
specifying the address and the number of 16 bit values to be read (quantity).
The default word order is little endian, but you can change this setting in the
module.
Modbus address
0
1
2
3
A complete measured value or a status value comprises 32 bits, so for a
measured value, you must read out two 16 bit values.
Use the Modbus functions "Write Single Register (0x06)" or "Write Multiple
Register (0x10)" to transfer cyclic data from the PLC to the indicator.
Modbus address
0
2.2 Parameters for acyclic data
Modbus functions "Read Holding Registers (0x03)" and "Write Single Register
(0x06)" or "Write Multiple Register (0x10)" are used to access acyclic data. As
Modbus holding registers always have 16 bit data, 8 bit data are also
accessed with 16 bits, but the MSB is ignored. Accesses to 32 bit values
require access to two holding registers. Data consistency is assured in all
cases.
The table below shows the assignment of the individual parameters ("Name",
"Data type" and "Description" columns) to the Modbus address ("Address"
column), and the number of registers required ("No. of registers" column). The
"DWS" and "DIS" columns indicate whether the function is available in the
respective electronics, and the "Doc." (documentation) column indicates which
operating manuals contain descriptions of the function (AED = AED/FIT
Online Help).
A3111−1.0 en/de/fr
Content (16 bits)
LOW measured value
status
HIGH measured value
status
LOW measured value
HIGH measured value
Content (16 bits)
Control word
ASCII command
MSS
MSV
ASCII command
CTL
5
HBM