Danfoss Modbus RTU Module User guide

User guide

Modbus RTU Module

for heat meter SonoMeter 30

Applications

Features

Power supply

Communication interface

The Modbus RTU module is destined to heat
meters in order the heat meters to Modbus RTU
network using EIA-485 channel.

• Galvanic isolation EIA-485 network interface used for easy and safe connection up to 256 devices
in one network bus.

• Modbus RTU Slave protocol is realized according to specifications by Modbus Organization.

Polarity independent connection for SELV power supply – connectors 60 and 61

Voltage: 12-24 V(AC/DC)
Maximum power consumption: 2 W max.
Typical supply current: 50 mA

Connectors 90 (noninverting, +) and 91 (inverting, -)

Communication protocol Modbus RTU

Baud rate (bits per second) 1200, 2400, 4800, 9600-default,19200,38400, 56000, 57600, 115200

Data format8E1

(8 data bits, even parit y bit, 1 stop bit)-default
8O1 (8 data bits, odd parity bit, 1 stop bit)
8N2 (8 data bits, none parity bit, 2 stop bits)

Status LED and Status
Button functionality

© Danfoss | 2018.02 BC262356385429en-000101 | 1

Status LED is signalizing every Modbus communication event. Status LED is blinking on during
request and response sending.

Press the button, then power on the module and hold the button pushed longer than 15seconds to
reset device to factory settings (set Modbus Slave ID todefault value 1, the Update Rate parameter to
default 10 minutes and the communication interface to defaults parameters –9600 bps baud rate and
8E1 data format).

User guide Modbuster RTU module for SonoMeter 30

Modbus RTU Module for
heat meters

Parameters which can be changed:

• ModBus address (Slave ID);

• Update Rate Data from Meter;

• Baud Rate

• Parity

• Stop Bits

Parameters can be changed using software called “Modbus Reader”.

1. First of all you need to open attached reading scenario called “Modbus.scn”. When it is opened,
the main window which present in.

Fig 1 will be seen.

2. Then change device address, default is “1”.

3. Then click “Port Settings”.

2 | BC262356385429en-000101 © Danfoss | 2018.02

User guide Modbuster RTU module for SonoMeter 30

Modbus RTU Module for
heat meters (continuo us)

4. Then immediately opens new window. In that new window choose the correctly parameters to
read device.

• Parity – “Even”

• Stop Bits – “1 bit”

• Bits – “8”

• Baud rate – “9600 (default)”
Then click “Ok”

5. Read the actual Modbus card.

6. In the value column near the parameter which you want to change simply enter the changeable
value ant then press the button “Send command”. After this the parameter will be changed. In
order to read Modbus card again you have to change “Port settings” or “Device address” if it has
been changed.

7. If you need reset the ModBus module, you need to turn off the power supply from the 230V. Wait
when the module discharge (about 5-10sec) and hold on the module “set” button then plug in
230V. You need to hold on the button until “LINK” led blinked. After all, the ModBus address back
to default address.

BC262356385429en-000101 | 3© Danfoss | 2018.02