Danfoss VACON 1000 Operating Manual page 35

VACON® 1000 Fieldbus Options
Operating Guide
Number Parameter
W2
W3
W4
W5
W6
W7
W8
W9
W10
W11
W12
3.4 Troubleshooting
3.4.1 General Instructions
When the AC drive control diagnostics detects an unusual operating condition, the drive initiates a notification visible, for example,
on the HMI. The display shows the number of the fault, the fault code, and a short fault description.
The fault can be reset with the Reset button or via the I/O terminal. The faults are stored in the Fault history menu which can be
browsed. For a list of all fault codes, see the VACON® 1000 Application Guide and Operating Guide.
When contacting Danfoss because of a fault condition, always provide:
• Texts and fault codes on the HMI
• Description of the problem
• Drive Info file
3.4.2 RS485 Bus Biasing
When none of the devices on the RS485 bus is sending data, all devices are in idle status. This being the case, the bus voltage is in
indefinite state, usually near 0 V due to the termination resistors. This can cause problems in character reception because the single
characters in serial communication begin with start bit referring to bus status '0' with voltage of less than -200 mV. Bus status '1'
corresponds to bus voltage of more than +200 mV. The RS485 standard considers the voltage interval -200 mV...+200 mV as an
undefined state. Therefore, bus biasing must maintain the voltage in status '1' (above +200 mV) also between the messages.
To bias the bus, add a separate active termination resistor designed for the RS485 bus (for example, Siemens active RS485 terminat-
ing element 6ES7972-0DA00-0AA0).
3.5 Specifications
Table 18: Modbus RTU Protocol Specifications
Data
Interface
Data transfer method
Transfer cable
Connector
Electrical isolation
Danfoss A/S © 2023.09
Modbus Address
15106
15109
15112
15115
15118
15121
15124
15127
15130
15133
15136
Details
RS485
RS485 MS/TP, half duplex
STP (Shielded Twisted Pair), type Belden 9841 or similar
2
2.5 mm
Functional
Function Code Data Format
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
3 (Read) Word
Modbus RTU/TCP
Data description
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