6 Configuration
Installation manual
21
EKMBPP1
Modbus adapter
4P720139-1B – 2023.09
6.3.2 Modbus registers
The EKMBPP1 supports 2 types of registers: holding registers and input
registers.
Register type Access Function(s)
Holding register Read/Write Control and command, readback and
monitoring
Input register Read-only Readback and monitoring
The input registers are used to access all analogue and digital values.
The register values are 2 byte (16 bit) values. Depending on the values
accessed, a number of specific conventions apply to the data types the
registers return:
Data type Value range Convention
Digital 0~1
▪
0: False
▪
1: True
Integer 0~65535 No value scaling required.
Temperature 0~65535
▪
To allow for greater precision,
temperatures values are
returned multiplied by 100.
▪
Negative temperature values are
returned as signed integers. Any
value >32767 is to be converted
into a negative value by
subtracting 65536 from it.
(a)
(a)
For example, a readback value of 2050 is a positive temperature
(<32767): 2050/100=20.50°C. However, a readback value of 65036
is a negative temperature (>32767): 65036−65536=−500. Dividing
−500 by 100 results in a temperature of −5.00°C.
Accessing the registers is done using any of the following standard
Modbus functions:
Function code (hex code) Function name Register count
03 (03h) Read holding register 1~10
04 (04h) Read input register 1~10
06 (06h) Preset single holding register 1
16 (10h) Preset multiple holding registers 1~10