Specifications

4P357732-1 – 2014.04 Page 57 of 58
6. Trouble shooting
Problem
Possible causes
Required actions
No Modbus
communication
No correct Modbus address setting was
present at power on of the Modbus
Interface DIII.
During power off:
Set DS2 according to the required
Modbus address.
See chapter “1.3.6 Dipswitch
meaning”.
The dipswitch on/off status is
detected only at the time of power
on of the PCB.
No Modbus address setting is set (=DS2:
Off/Off/Off/Off).
Set DS2 according to the required
Modbus address.
See chapter “1.3.6 Dipswitch
meaning”.
Only firmware is present on the Modbus
Interface DIII. HAP: is blinking at a fast rate
of 200ms meaning firmware is running.
Upload the latest application
software.
See chapter “4.2 Software update
with Updater”.
Software update
with updater (via
RS485) fails
DS2 is set to off/off/off/off. (meaning no
communication on RS485).
Change DS2 settings to e.g.
off/off/off/on.
Refer to chapter “4.2.3 Method 2)
Update with a USB/RS485
converter.”.
A BMS set of a
holding register is
not reflected on the
actual unit.
Modbus Interface DIII sends the command
to a unit when the value of a Holding
Register is changed. Especially in case that
indoor units are operated from the user
interface.
The BMS should always get the
status of indoor units and copy the
received status to the Holding
Registers.
Refer to chapter “2.3.2 Monitor and
operate units from the BMS”.