User's Manual

905U-K.MAN Rev. 1.1 January 2002
 ELPRO Technologies Pty Ltd Page 9
• Setpoint Status (digital signal set or reset depending upon the value of the analogue signal
compared to a high and a low setpoint value configured in the 905U-K)
• Battery Low Voltage (digital signal set when internal battery voltage is low).
1.3 Power Supply
The power consumption of the 905U-K is very small as it conserves power by reverting to
“sleep” mode between transmissions.
The 905U-K can be powered from an external 12V DC supply, or a 5.4 – 30V battery supply.
The battery supply can be an external battery pack. The 905U-K units provide an internal
alarm on low battery voltage - this alarm may be transmitted by radio for warning purposes.
The low battery alarm indicates that there is approximately 2% of battery capacity left.
1.4 Radio Transmitter
The 905U-K has an internal radio transmitter that operates on unlicensed spread spectrum
radio channels in the 902 - 928MHz UHF band.
It is suitable for use in utility industries such as electricity, water and gas, as well as a cost
effective solution for short range applications in factories and industrial plants.
The transmitter is preset in the factory to suit the unlicensed frequency requirements in each
country. The maximum transmitter power is 1W. In countries where there are no unlicensed
radio channels, a radio licence may be required each time the product is used. Please contact
one of our worldwide distributors for further information.
To extend radio range, 905U modules can be used as repeaters. Up to five repeaters can be
configured for each input-to-output link. The configuration is done at the 905U-K module
where the input signal is - no additional configuration is required at the 905U modules. The
transmitted radio message will include the address of repeater modules - modules with these
addresses will re-transmit the messages.
1.5 Configuration
Each module must be configured before it can be used. Configuration is performed using a PC
(or a laptop computer) connected to the module via the internal RS232 port on the 905U-K.
905U-K configuration software is required and is provided with each order.
Configuring a module requires the entering of “input mappings” and setting operating
parameters for each input. An “input mapping” links an input signal to an output channel at a
remote module (or a “destination address”). An input mapping is entered for each input signal
(external and internal) which is used.