Page 2 of 9 November 2021
ELPRO_415U-IAS_IntelligentAntennaSwitch_UserManual_1.0.docx
System Design
The 415U-IAS is designed to be installed with an existing legacy system. The 415U-BSR monitors
MODBUS messages sent from a central SCADA computer and monitors MODBUS responses from
field sites. The system can use either RS-232 serial communications or it can communicate over
TCP-IP link.
The legacy system must use MODBUS protocol, and the radio network must be a polling-only system
(No background communications between the legacy base station and legacy field sites).
The process for system upgrade is:
1) Install the 415U-IAS and 415U-BSR at the base station
2) Connect to the SCADA computer and the Legacy Base Radio
3) Ensure the Legacy system is operating correctly, with all existing sites remaining operational.
The 415U-IAS will switch to the Alternate port each time a message is sent to a Legacy site.
4) Begin upgrading Legacy radios with new ELPRO 415U series radios. As each site is
upgraded, the Base station should detect the change, and the 415U-IAS should switch to the
Primary port when polling the ELPRO 415U series radios.
Redundancy
Some systems require a level of redundancy to support increased reliability. Once the system
upgrade is complete, the ELPRO 415U system provides hot standby redundancy. During the system
upgrade, the 415U-BSR is set up for cold standby. Only one of the two radios in the 415U-BSR is
powered at any time. The two RF Switches on the 415U-IAS operate together. To switch to the
standby 415U-BSR radio, switch the connections on the rear panel from the “Repeater 1” connections
to the corresponding “Repeater 2” connections.
If a redundant system is being implemented, then connect both RF Switches on the 415U-IAS. If
redundancy is not to be implemented, then only connect to RF Switch 1. Refer to the install guide for
a detailed diagram for connecting redundant systems.
Connection to the SCADA computer
Most existing systems will be using an RS-232 serial connection between the SCADA computer and
the Legacy base radio. The 415U-IAS allows either RS-232 communications or communication over a
TCP-IP stream.
To connect to the SCADA computer using RS-232 serial, connect to the DB-25 female connector
marked “SCADA Computer” on the front of the 415U-IAS unit. Data to and from the SCADA computer
is transferred to the 415U-BSR RS-485 serial port. Ensure the data rate and character format on the
415U-BSR RS-485 serial port match the data rate of the SCADA computer (See “SCADA Computer
RS-232 Serial connection ” on page 4 below).
To connect to the SCDA computer using TCP-IP stream, connect the Ethernet cable to the ethernet
port on the 415U-BSR (See “Multicast Pipe Manager Configuration” on page 4 below).
Connection to the Legacy Base Radio
Connect the Legacy Base Radio to the DB-25 Male plug on the front of the 415U-IAS marked “Legacy
Radio”. When the Legacy radio is a DB-25 Female (DCE), you can connect using a standard DB-25
extension cable. When the Legacy radio is turned on and the connection is made, the yellow LED
marked “ACT” will come on and will flicker with traffic between the 415U-IAS and the Legacy Radio.
Messages to and from the legacy radio are sent and received on the 415U-2 BSR RS-232 serial port.
Ensure the data rate on the 415U-BSR RS-232 serial port to match the data rate of the Legacy Base
Radio (See “MODBUS Migration Router configuration” on page 3 below).
