Westermo RM-505U-2-E - Manual (Page 9)

User Manual
MAN_505_1.7.DOC Page 9
2 OPERATION
2.1 Normal Operation
Once configured using the 505U configuration software, the 505U module will normally be in
“sleep” mode to conserve power. During sleep mode, the microprocessor controller powers down,
and the analogue loop supply is turned off. The microprocessor will automatically “wake up” and
revert to full operation if a digital/pulse input changes (on to off, or off to on), or every 0.5 seconds
to check if a timed update transmission is due to be sent.
Normal operation of the 505U is indicated by a brief flicker of the OK LED light on the front panel
approximately every 10 seconds.
2.2 What information is transmitted over the radio?
The 505U modules transmit the value of the input signal in a data frame. The data frame includes a
system address, and the "address" of the transmitting (source) 505U module and the receiving
(destination) 105U module, so that each transmitted message is acted on only by the correct
receiving unit. The system address is a common address used by all modules in the same system.
This allows multiple systems to operate within the same radio range without "cross-talk" between
systems.
The user configures these addresses as part of the module configuration. Each transmitted message
also includes error checking to ensure that no corruption of the data frame has occurred due to noise
or interference. If repeater modules are being used, then the addresses of these intermediate
modules are also included in the data frame.
The user can configure the 505U to transmit each message from one to five times to ensure that at
least one of the messages is received correctly. Each repeat transmission will occur at random
intervals between one and four seconds.
2.3 How often is the input information sent by radio?
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Change messages. The 505U transmits the value of an input signal whenever the signal changes.
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Update messages. The input value is also transmitted if the signal has not changed within a pre-
configured update time (configurable 10 seconds to 5 days).
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Paralysis. When a 505U transmits a message for a particular input, the 505U will not transmit
another message for this input within a configured time period. This time is called the paralysis
time, and may be used to prevent a lot of messages being transmitted if an input changes
frequently. The paralysis time may be set from zero to 127.5 seconds for each input. For
example, assume the paralysis time on an input is 30 seconds. If the input changes, then the
505U will transmit a message, however it will not transmit another message for this input during
the next 30 seconds, regardless of changes to the input signal. Note that paralysis time does not