Introduction; Protocols; Modbus; Dnp3 - HindlePower AT Series Operating Instructions Manual

INTRODUCTION / PROTOCOLS

1 Introduction

The AT Series Communications option allows the user to remotely monitor and control the
AT Series Battery Charger over a serial connection. Everything that the user can do at the
charger's front panel display is accessible remotely. The communications option supports
DNP3 Level 2 and Modbus protocols over RS-232 or RS-485 serial communications.
Configuration is done by DIP switches and a setup program for additional parameters. The
communications board supports baud rates of 9600 bps and 19200 bps.

2 Protocols

2.1 Modbus

The communications option can be setup to communicate on standard Modbus networks
using either of two transmission modes: ASCII (American Standard Code for Information
Interchange) or RTU (Remote Terminal Unit). The advantage of ASCII allows less strict
serial timing requirements without causing communication errors. The advantage of RTU
allows more data to be transmitted than ASCII mode for higher throughput.
Modbus ASCII mode supports the following serial settings:
• No parity, 7 data bits, 2 stop bits
• Even parity, 7 data bits, 1 stop bit
• Odd parity, 7 data bits, 1 stop bit
Modbus RTU mode supports the following serial settings:
• No parity, 8 data bits, 2 stop bits
• Even parity, 8 data bits, 1 stop bit
• Odd parity, 8 data bits, 1 stop bit
Refer to the Modbus section on page 28 for information on its implementation.

2.2 DNP3

The communications option supports DNP3 Level 2. This implementation of DNP3 meets
Level 2 conformance and supports change events with unsolicited messaging.
The DNP protocol supports the following serial settings:
• No parity, 8 data bits, 1 stop bit
• No parity, 8 data bits, 2 stop bits
• Even parity, 8 data bits, 1 stop bit
• Odd parity, 8 data bits, 1 stop bit
Refer to the DNP V3.00 section on page 17 for information on its implementation.
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