Westermo RM-505U-2-E - Manual (Page 7)

User Manual
MAN_505_1.7.DOC Page 7
Examples: motor fault, tank overflow, intruder alarm
Pulse signals - use the same input as the digital input
Examples: electricity metering, fluid flow, raingauge
Analogue continuously variable signals (0-20mA, 4-20mA, 0-10mA) - 505U-2 only
Examples: measured tank level, measured process temperature
Two internal signals may also be transmitted to outputs in the network:
•
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 505U)
•
Battery Low Voltage (digital signal set when internal battery voltage is low).
1.3 Power Supply
The power consumption of the 505U is very small as it conserves power by reverting to “sleep”
mode between transmissions.
The 505U can be powered from an external 12V DC supply, or a 3.5 – 5V battery supply. The
battery supply can be either internal AA alkaline or lithium batteries, or an external battery pack.
The 505U-2-B units provide an internal alarm on low battery voltage - this alarm may be transmitted
by radio for warning purposes. No low battery alarm is provided on externally powered models
(505U-2-E). The low battery alarm indicates that there is approximately 2% of battery capacity
left.
1.4 Radio Transmitter
The 505U has an internal radio transmitter that operates on unlicensed radio channels in the 400 –
500MHz UHF band. A radio licence is not required for the 505U in many countries and has an
operating range of several kilometres.
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 500mW using an external power supply, or 250mW using the
internal battery supply (500mW available using a 3dB antenna). 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, 105U 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 505U module where the
input signal is - no additional configuration is required at the 105U modules. The transmitted radio
message will include the address of repeater modules - modules with these addresses will re-
transmit the messages.