Modbus Communications; Modbus Protocol - GE D90 Plus Instruction Manual

CHAPTER 6: COMMUNICATIONS

Modbus communications

Modbus protocol

PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
IEC 61850 Available.
Range: No, Yes
This actual value indicates if the IEC 61850 protocol in enabled on the Ethernet ports.
Configure IP Network Status
Range: OK, PORT 1 NETMASK ERROR, PORT 2 NETMASK ERROR, PORT 3 NETMASK ERROR,
PORT 1 IP ADDR RSVD, PORT 2 IP ADDR RSVD, PORT 3 IP ADDR RSVD, PORT 1 IP ADDR
LPBK, PORT 2 IP ADDR LPBK, PORT 3 IP ADDR LPBK, PORT 1 IP ADDR NETWK, PORT 2 IP
ADDR NETWK, PORT 3 IP ADDR NETWK, PRT 1-2 SUBNET OVRLP, PRT 1-3 SUBNET OVRLP,
PRT 2-3 SUBNET OVRLP, > 1 GATEWAY DEFINED
This actual value indicates the validity of the IP parameters applied to the network stack.
For details on the status values, see
for ports 2 and 3 exist only when the D90
The Modicon Modbus protocol is supported by the D90
RS485 serial link (Modbus RTU) or via Ethernet (Modbus/TCP). The D90
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.
Plus
See the D90 Communications Guide for 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 69: 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 COMMUNICATIONS
Ethernet ports on page 84. The Ethernet parameters
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contains a communications card.
Plus
. Modbus is available via the
Plus
Plus
always acts as a
. Each device must have a
91