Modbus Communication Setting
General Settings
|
Item |
Setting |
|---|---|
|
Address |
1–99 |
|
Broadcast |
No |
|
Transmission mode |
RTU |
|
Baud rate (bps) |
Auto(1): auto mode, support Baud rate of 9600, 19200, 38400, 57600, 115200 9600 19200 |
|
Parity |
O: Odd parity E: Even parity N: None parity |
|
Data bit number |
8 |
|
Stop bit number |
1(2) |
|
(1)The first 10 data packages will not be responded when Auto mode is adapting. (2) The stop bit is set to 1 by default for all parity setting. |
|
Configuring Modbus Address
RDM module supports Modbus addresses from 1 to 99. It can be set using the 2 setting knobs on the module.
The address setting will be effective once the contactor is powered on. If you want to change the address setting, disconnect the power, modify the setting and power on the contactor again.
Follow the steps below to set the Modbus address:
-
Insert a Phillips screwdriver to the setting knob.
-
Turn the knobs to set the tens-digit and ones-digit of the Modbus address.
Configuring Baud Rate and Parity
RDM module supports baud rate up to 115200 bps and setting parity to odd, even or none.
Use the same knob to set the baud rate and parity. The setting will be effective once the contactor is powered on. If you want to change the setting, disconnect the power, modify the setting and power on the contactor again..
Modbus Function Code
RDM module supports the following Modbus function codes:
-
Read: 03 - Read Holding Registers
-
Write: 06 - Write Single Register
-
Write: 16 - Write Multiple Registers
Modbus Exception Code
The following table describes the exception codes handled by RDM module.
|
Exception code |
Name |
Description |
|---|---|---|
|
01 (0x01) |
Illegal function |
The function code received in the request is not an authorized action for the server. |
|
02 (0x02) |
Illegal data address |
The data address received by the server is not an authorized address for the server. |
|
03 (0x03) |
Illegal data value |
The value in the request data field is not an authorized value for the server. |
|
04 (0x04) |
Server failure |
The server fails to perform a requested action because of an unrecoverable error. |
Digital Output Setting
Digital output for diagnosis indications except for internal malfunction can be set to enabled or disabled. By default, all diagnosis indications except for internal malfunction are disabled. Internal malfunction indication is fixed as enabled.
Set the bit to 1 to enable the digital output of alarms, and set to 0 to disable it. The reserved bits without any diagnosis indication should also be set to 0. The digital output configuration is written to the register 61701 with Modbus function code 06 or 16. See Modbus Registers for more information.