Setting Up Rs485 Serial Communication - Danfoss VLT CDS 803 Manual

VLT® Compressor Drive CDS 803
Design Guide
The following illustration shows all the drive control terminals. Applying start (terminal 18), connection between terminals 12-27,
and an analog reference (terminal 53 or 54, and 55) make the drive run.
The digital input mode of terminal 18, 19, 27, and 29 is set in parameter 5-00 Digital Input Mode (PNP is default value).
BUS TER.
OFF ON
61 68 69
18 19 27 29 42
Illustration 32: Control Terminals

6.4 Setting Up RS485 Serial Communication

6.4.1 RS485 Features
RS485 is a 2-wire bus interface compatible with multi-drop network topology. This interface contains the following features:
• Ability to select from the following communication protocols:
- FC (default protocol)
- Modbus RTU
• Functions can be programmed remotely using the RS485 connection or in parameter group 8-** Communications and Options.
• A switch (BUS TER) is provided on the control card for bus termination resistance.
Altering between the supported communication protocols can be accessed and changed via the LCP as parameter 8-30 Protocol is
not available in VLT® Motion Control Tool MCT 10.
6.4.2 Configuring RS485 Serial Communication
Procedure
1. Connect RS485 serial communication wiring to terminals (P RS485) 68 and (N RS485) 69.
- Use shielded serial communication cable.
- Properly ground the wiring. Refer to
Danfoss A/S © 2021.05
45 50 53 54
12 20 55
N O T I C E
6.5.5 EMC-compliant Electrical
Electrical Installation
Installation.
AJ330233902305en-000201 / 130R0596 | 51
Considerations