Dressler CESAR 1312, User Manual

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CESAR 1312 (E) Communication Interfaces 4-57
CESAR™ 1312 Generator
You can control the CESAR generator through a network using a Modbus/
TCP connection.
Figure 4-43 illustrates the connector.
Figure 4-43. Ethernet connector
The following sections describe some of the attributes of CESAR generator
Modbus/TCP communication. For general information about the Modbus/TCP
protocol, visit the Modbus Users Web Site at: www.modbus.org. For more
information on connecting to the unit through the Ethernet port, see
“Connecting and Setting Ethernet (Modbus/TCP) Communication” on
page 5-9
and “Connecting to an Ethernet-Enabled Unit With a Web Browser”
on page 5-49 .
The CESAR generator does not directly implement Modbus/TCP. Instead, a
program running on the interface board accepts Modbus/TCP packets from
the
Host , sends appropriate AE Bus commands to the CESAR generator
using the internal RS-232 interface, and forms an appropriate reply packet.
The system supports up to 6 Modbus/TCP connections to port 502.
Registers are defined in an absolute-zero-based format.
Note: When using third-party tools, make sure to select zero-based format.
UNDERSTANDING MODBUS/TCP COMMANDS AND
REGISTER TYPES
The CESAR generator uses the class 2 definition of Modbus/TCP. FC23 is
used to map the CESAR generator’s AE Bus commands to the Modbus/TCP
packet. You can use FC23 to run all common CESAR generator commands.
For more information and specific register information, see page
4-58 .
The CESAR generator may reply to Modbus/TCP commands with the
following exception codes:
• 01 (illegal function)
• 02 (illegal register reference)
• 03 (illegal data value)