Modbus Protocol; Modbus User Map - GE D90 Plus Instruction Manual

CHAPTER 6: COMMUNICATIONS

Modbus protocol

Modbus user map

PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
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.
Plus
See the D90 Communications Guide for additional details on the Modbus protocol and
the Modbus memory map.
The Modbus server can simultaneously support one client over serial RS485 and four
clients over Ethernet. 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.
Plus
The D90 operates as a Modbus slave device only.
Select the Settings > Communications > Modbus > Protocol menu item to open the
Modbus protocol configuration window.
Figure 83: Modbus protocol configuration settings
The following Modbus protocol settings are available.
Modbus Slave Address
Range: 1 to 254 in steps of 1
Default: 254
This setting specifies the Modbus slave address for the D90
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.
Modbus TCP Port Number
Range: 1 to 65535 in steps of 1
Default: 502
This setting specifies the Modbus TCP port number for Ethernet communications. Power
Plus
to the D90 must be cycled for changes to this setting to take effect.
The Modbus user map provides read-only access for up to 256 registers. To obtain a
memory map value, enter the desired address in the
converted from hexadecimal to decimal format). The corresponding value (if programmed)
is displayed in the value field. A value of "0" in subsequent register address lines
automatically returns values for the previous address lines incremented by 1. An address
value of "0" in the initial register means none and values of "0" will be displayed for all
registers. Different address values can be entered as required in any of the register
positions.
Select the Settings > Communications > Modbus > User Map menu item to open the
Modbus user map configuration window.
MODBUS COMMUNICATIONS
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. Each device must have a
field (this value must be
Parameter
103