105 Radio/Serial Telemetry Module
User Manual
Page
26
©
January 2004
Repeaters
can be used in a system to increase range. Each 105U unit can be configured to
act as a repeater. When configuring an input to be mapped to an output, the communications
path to the output unit, including the repeater addresses is specified. The 105U acts as a
digital repeater
, that is, the signal is decoded and then retransmitted “as new”.
Example Repeater Communications
Unit A DI 1 mapped to Unit D DO1 via Units B & C
Unit A
Unit B
Repeater
Unit C
Repeater
Unit D
•
DI 1 is turned
on
•
Transmit
•
Receive
Acknowledge
•
Receive
•
Transmit on with
Acknowledge
•
Receive
Acknowledge
•
Receive
•
Transmit on with
Acknowledge
•
Receive
Acknowledge
•
Receive
•
Transmit
acknowledge
•
DO 1 is
turned on
3.1.2
Change of state conditions
The 105 module transmits a data message whenever it detects a "change-of-state" on one of
its input signals. A "change-of-state" of a digital or digital internal input is a change from
"off" to "on" or vice-versa provided the change is sustained for 0.5 second (i.e. 0.5 second
debounce). The debounce delay is configurable.
In addition to "change-of-state" transmissions, each module will transmit the status of each
input to its corresponding output every ten minutes (configurable). These
updates
mean that
the outputs are set to the current input values regularly, even where no “change-of-state” has
occurred. These update transmissions increase the accuracy of the output and give extra
system reliability. Update times can be configured from 10 seconds to 16 minutes on the
105-1, -2 and –3 modules, and from 10 seconds to 5 days on the 105-4. Note that the
accuracy of the time period is approx 0.5%.
Analogue Change-of-state
A "change-of-state" for an analogue input, battery voltage or pulse input rate is a change in
value of the signal of 3% (configurable) since the last transmission. Note that the sensitivity
of 3% refers to 3% of the analogue range, not 3% of the instantaneous analogue value. That
is, if an analogue input changes from 64% (14.24 mA) to 67% (14.72 mA), a "change-of-
state" will be detected. This “change-of-state” sensitivity is configurable between 0.8% and
50%.
Analogue inputs are digitally filtered to prevent multiple transmissions on continually varying
