Nibe MODBUS 40 User Manual

Communication
TIP
ModbusManager can be downloaded via
www.nibe.se/kommunikation.
Read the values
There are two ways of reading the values from the heat
pump/indoor module, automatically or manually.
■
Automatic reading: can retrieve up to 20 predefined
parameters at the same time.
■
Manual reading: takes longer and only one value at
a time can be retrieved.
Automatic reading
Caution
Maximum 20 parameters defined in the
LOG.SET file can be used by MODBUS 40 (cor-
responds to 20x16-bits Modbus-register). If
more parameters are selected, the first 20
parameters are used.
A small number of parameters are 32-bit, and
therefore take up two registry locations, which
means that fewer parameters can be read.
1.
Create a LOG.SET file that contains the predefined
values that are to be read out. The file is created
in ModbusManager. See section "Create a log set-
tings file in ModbusManager" for instructions.
2.
Save LOG.SET to a USB-memory.
3.
Insert the USB-memory into the heat pump's/in-
door module's display unit.
4.
Enter menu USB.
5.
Enter menu "logging".
6.
Tick “activated".
7.
Remove the USB-memory.
The heat pump/indoor module will now update the
values for all defined parameters twice a second.
Retrieve the values for the Modbus-master by using
the "Read holding registers" command with the desired
parameter addresses. Use ModbusManager, see
LOG.SET in a text editor or see the examples list on
page 19 to see which parameter address a value has.
See section The Modbus command on page 19 for
further information about different commands.
17
GB

Nibe MODBUS 40 Specifications

General

Category	Control Unit
Communication	RS485
Communication protocol	Modbus RTU
Data bits	8
Parity	None, Even, Odd
Stop bits	1, 2
Connection type	Screw terminal
Power supply	24 V AC/DC
Protection class	IP20
Relative humidity	5% to 95% (non-condensing)
Storage temperature	-40°C to +70°C

Summary

Mounting

Installation

Connecting to the heat pump/indoor module

Details how to connect the MODBUS 40 to various NIBE heat pumps and indoor modules.

Exhaust air heat pumps connection

Details connections for exhaust air heat pumps like F370, F470, F750.

Air/water heat pumps connection

Details connections for indoor modules like VVM 310, VVM 320, VVM 325.

VVM 500 module connection

Details connection for VVM 500 indoor module.

Control module SMO 40 connection

Details connection for SMO 40 control module.

Several accessories with MODBUS 40

Connecting to Modbus-master

Settings

Communication

Read the values overview

Explains how to retrieve data, offering automatic and manual methods.

Automatic reading process

Details the process for automatically retrieving up to 20 predefined parameters using a LOG.SET file.

Manual reading process

Explains manual data retrieval, one value at a time, for the Modbus-master.

The Modbus command

Details the Modbus commands for reading and writing registers and device identification.

Create a log settings file in ModbusManager

Troubleshooting

MODBUS 40 no contact issues

Addresses issues where MODBUS 40 fails to communicate with the heat pump/indoor module.

Technical data