Key Terms; Ethernet Modbus Device Prerequisites - Siemens US2:9810T24V User Manual

Communications
Your device can function as a Modbus client or Modbus server, depending on how it is configured.
Your device comes with Modbus server functionality configured and ready to use. You can add
custom Modbus information to the default Modbus server data provided by your device.

Key terms

Term
Modbus gateway
Modbus client (historically
known as Modbus master)
Modbus RTU
Modbus register/address
Modbus server (historically
known as Modbus slave)
Modbus TCP
Modbus unit ID
You can download your device's Modbus map from www.usa.siemens.com/pds and get
additional information about the Modbus protocol from www.modbus.org.

Ethernet Modbus device prerequisites

For your meter to operate as an Ethernet Modbus device, you must complete some prerequisite
configuration.
NOTE: You do not need to perform any Modbus-specific configuration for your meter to function
as a Modbus client device over Ethernet.
Prerequisite
Ethernet
IP address
Port
97
Definition
A communications method that lets you communicate through an
Ethernet gateway device to a Modbus serial network connected to
that device.
A device that issues commands and receives responses from
Modbus server devices. Serial Modbus networks can only have
one Modbus client per network.
Serial Modbus protocol format; Modbus RTU transmits data using
binary. Server and client devices must use the same format.
Identifies the data to read/write. Modbus register maps are
available for Modbus client devices and detail the information
available from the client device. More than one register may be
used to store a single value.
A device that responds to Modbus commands and performs
actions or provides information back to the Modbus client. Most
Modbus networks contain multiple server devices.
The Ethernet Modbus protocol format.
The identifier for a client Modbus device.
Description
All devices must have a working Ethernet connection.
All devices must have a unique IP address.
All devices must be communicating over Ethernet port 502 for
Modbus TCP.
9810 series - User manual
7EN05-0390-08