Parameter configuration, Supported modbus function codes – Rockwell Automation 22A PowerFlex 4 User Manual FRN 6.xx User Manual

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C-2

RS485 (DSI) Protocol

Standard RS485 wiring practices apply. Termination resistors need to be
applied at each end of the network cable. RS485 repeaters may need to
be used for long cable runs, or if greater than 32 nodes are needed on the
network.

Control Terminal 16 on the PowerFlex 4 must also be connected to PE
ground (there are two PE terminals on the drive). See

Figure 1.5

for more

information.

Parameter Configuration

The following PowerFlex 4 parameters are used to configure the drive to
operate on a network.

Supported Modbus Function Codes

The peripheral interface (DSI) used on PowerFlex 4 drives supports
some of the Modbus function codes.

Important: Modbus devices can be 0-based (registers are numbered

starting at 0) or 1-based (registers are numbered starting at
1). Depending on the Modbus Master used, the register
addresses listed on the following pages may need to be
offset by +1. For example, Logic Command may be register
address 8192 for some master devices (e.g. ProSoft
3150-MCM SLC Modbus scanner) and 8193 for others
(e.g. PanelViews).

Parameter

Details

Reference

P036 [Start Source]

Set to 5 “RS485 (DSI) Port” if Start is controlled from
the network.

Page 3-9

P038 [Speed Reference]

Set to 5 “RS485 (DSI) Port” if the Speed Reference is
controlled from the network.

Page 3-11

A103 [Comm Data Rate]

Sets the data rate for the RS485 (DSI) Port. All nodes
on the network must be set to the same data rate.

Page 3-23