Westermo RM-80 - Manual (Page 28)

28 6193-4201
Duty Cycle Alarm
ThresholdDuty cycle alarm
activation point
In CE countries, the 869.4 MHz 500mW band has a
regulated transmit duty factor of 10%. The Access Point
calculates the system duty cycle and will set an internal
alarm flag if the actual duty cycle exceeds this param-
eter. Refer to more information on Duty Cycle calcula-
tions at the end of this section. The internal alarm flag
can be configured to drop to wireless link or to set the
digital output channel (refer Digital I/O configuration).
Default value is 10%.
Duty Cycle Alarm
Minimum
The internal alarm flag will reset when the actual duty
cycle drops below this value – default value is 9%.
Duty Interval The time period over which the duty cycle is calculated
– default is 60 minutes
Current Duty Cycle
Achieved A display of the current duty cycle value.
Drop Radio Link on Duty
Cycle Alarm Allows the internal duty cycle alarm to force the
Access Point to reduce radio activity. The Access Point
will disassociate from all Client units and will not allow
re-association until the duty cycle alarm resets.Default
value is “not selected”.
Apply Changes Update settings.
Apply Changes and Save Update settings and save to non-volatile memory.
Duty Cycle Calculations
CE radio regulations limit the transmit duty cycle of the 869.525MHz 500mW channel to
10%. That is, the total transmission time of the radio system should be less than 10% of
the total time.
The Access Point calculates the duty cycle, and provides an internal alarm flag if the
calculated duty cycle exceeds the user-configured setpoint value (default value is 10%).
The alarm flag will reset when the duty cycle drops below a user-configurable “minimum
value” (default 9%). The internal flag can be used to automatically reset the wireless links
between the Access Points and Clients to avoid duty cycle exceeded the configured limit
- this feature needs to be configured by the user; the default setting is “no automatic
reset”. The calculated duty cycle can also be viewed.
The duty cycle is calculated over a duty interval period which is also user-configurable
(default is 60 minutes). The transmission time for each 5 second block is stored. The
duty cycle is calculated every 5 seconds by summing the transmission times over the
interval period and expressing this as a percent of the interval period. For example, if
the interval period is 60 minutes, then the duty cycle is the sum of the transmit times in
the most recent 720 x 5-sec blocks, divided by the interval period.
A calculated duty cycle of 10% indicates that the total transmission time has reached 360
seconds in the previous 60 minutes.