Modbus - GE Multilin 350 Series Instruction Manual

CHAPTER 6: SETPOINTS
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
Courtesy of NationalSwitchgear.com
Figure 6-2: Serial port configuration settings
The following settings are available to configure the RS485 port.
BAUD RATE
Range: 9600, 19200, 38400, 57600, 115200
Default: 115200
This setting specifies the baud rate (bits per second) for the RS485 port.
PARITY
Range: None, Odd, Even
Default: None
This setting specifies the parity for the RS485 port.

6.2.3.2 Modbus

The Modicon Modbus protocol is supported by the 350. Modbus is available via the RS485
serial link (Modbus RTU). The 350 always acts as a slave device, meaning that it never
initiates communications; it only listens and responds to requests issued by a master
device. A subset of the Modbus protocol format is supported that allows extensive
monitoring, programming, and control functions using read and write register
commands.Refer to the 350 Feeder Protection System Communications Guide for
additional details on the Modbus protocol and the Modbus memory map.
The Modbus server can simultaneously support two clients over serial RS485. The server is
capable of reporting any indication or measurement and operating any output present in
the device. A user-configurable input and output map is also implemented.
The 350 operates as a Modbus slave device only
Select the Settings > Communications > Modbus > Protocol menu item in EnerVista SR3
Setup software, or the
SETPOINTS > S1 RELAY SETUP > COMMUNICATIONS > MODBUS
path to set up the modbus protocol as shown below.
PROTOCOL
Figure 6-3: Modbus protocol configuration settings
The following Modbus settings are available:
MODBUS SLAVE ADDRESS
Range: 1 to 254 in steps of 1
Default: 254
This setting specifies the Modbus slave address . Each device must have a unique
address from 1 to 254. Address 0 is the broadcast address to which all Modbus slave
devices listen. Addresses do not have to be sequential, but no two devices can have the
same address or conflicts resulting in errors will occur. Generally, each device added to
the link should use the next higher address starting at 1.
S1 RELAY SETUP
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