Operating Instructions

Communication via RS485
5.4 Communication using Modbus RTU
Fieldbuses
126 Function Manual, 04/2018, FW V4.7 SP10, A5E34229197B AE
5.4.1
Basic settings for communication
Overview
Depending on the particular inverter, you have the following options when setting
communication via Modbus RTU:
● For all inverters with an RS485 interface:
21 "USS Fieldbus"
● For inverters with a CU230P-2 HVAC / CU230P-2 BT
109 "BT Mac 9: Modbus RTU Fieldbus"
For additional information, please refer to the operating instructions of your inverter.
Overview of the manuals (Page 232).
Procedure with default setting 21 "USS Fieldbus"
Proceed as follows to set communication via Modbus RTU:
1. Activate communication via the RS485 interface using one of the following options:
– With Startdrive during commissioning step "Default setting of setpoint/command
sources":
21: USS fieldbus
– With the BOP-2 during the basic commissioning under step "MAc PAr P15":
FB USS
– Via parameter number:
p0015 = 21
2. Set the bus protocol via p2030:
p2030 = 2
3. Set the inverter address.
4. Make additional changes based on the parameters listed in the following section.
5. If you are working with Startdrive, back up the settings so they are not lost if the power
fails.
You have now made the settings for communication via Modbus.
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