APPENDIX A
33
What language (protocol) does the AT Communications Module use?
The AT Communications Module utilizes two protocols (languages): Modbus and DNP3.
What is the difference between Modbus and DNP3?
Modbus
is an industrial protocol that has been used for many years. There are two variations of the
Modbus protocol: ASCII and RTU.
DNP3
is a newer protocol developed specifically for the utility industry. DNP3 can be configured so
that if an event occurs, the charger will send a message to the computer system of any changes. This is called
unsolicited messaging. DNP3 with unsolicited messaging enabled detects the alarm and notifies the computer
system immediately instead of waiting for the computer system to poll for the status of the alarm.
Both protocols allow the computer system to query the charger for the current status.
What level of DNP3 does the AT Communications Module support?
The AT Communications Module supports DNP3 Level 2 with some advanced features. Refer to the
operation manual for the implementation of DNP3.
Can I communicate over the telephone?
Yes. A modem can be used to connect the AT Communications Module to an analog phone line. The
modem is should be set to auto-answer. The computer system will also need a modem. The computer system
will dial out to the AT Series charger. The modem connected at the charger will answer the call and start
communicating. Refer to the operation manual for connection details.
Will this work with my existing SCADA system?
The computer system can be a SCADA (supervisory control and data acquisition) system. SCADA
will monitor or log the parameters of the charger and other devices in the facility. There are many different
versions of SCADA software available for different types of industries and features. They communicate using
industrial communication protocols such as Modbus and DNP3. The SCADA software is configured for the
charger’s data and a display screen is designed to display the information for the operator. The screen can be
setup to display and allow control over the operation of the charger. HindlePower does not sell or maintain
SCADA systems.
Can I connect the AT Series charger to Ethernet network?
The AT Communications Module does not support Ethernet, however there is a device that can
connect the serial network to an Ethernet network. This device is called an Ethernet bridge. The Ethernet
bridge is protocol specific either Modbus or DNP3.
How do I configure the AT Communications Module control board?
For simple applications the board can be configured using DIP switches. The DIP switches set the
Protocol, serial type (RS-232 or RS-485), serial speed (baud rate), Modbus protocol, and the Modbus slave
address. For the more advanced configuration parameters used for the DNP3 protocol, a computer is required
to configure the parameters.
Can the AT Communications Module be added to an old charger in the field?
Yes. The communications option can be added to a charger in the field.
How do I know if the AT Communications Module will fit into my charger?
AT10.1 and AT30 Series battery chargers manufactured before January 1, 2003 will require the Main
Control pc board (A1) to be replaced or reprogrammed to add the update software, supporting the
Communications option. Chargers that have an EN0024-00 type Main Control pc board (A1) will need
replacement. Chargers that have an EN5002-00 (Rev. 0, 1, or 2) type Main Control pc board (A1) will need
replacement. Chargers that have an EN5002-00 (Rev. 3 or higher but do not have software Rev. 3.00 or higher)
need to be reprogrammed. Chargers that have an EN5002-00 (Rev. 3A or higher and have software Rev. 3.00
or higher) already support the Communications option.
