User Manual

“Halo” System: Communication Protocol 970-00002-000
EXI Wireless Systems, Confidential Page 22 of 33 July 27, 1999
Table 6 “High_ID” and “Low_ID” Switch
Switch Setting Selected Tags
High_ID > Low_ID All Tags with selected digit (switch ID Range) equal or between the
two numbers are selected.
High_ID < Low_ID All Tags with selected digit (switch ID Range) lower then or equal
to “High_ID” and all Tags with selected digit greater or equal of
“Low_ID” are selected
High_ID = Low_ID Only Tags with selected digit (switch ID Range) equal “High_ID”
(or “Low_ID”) are selected
5.2.2.12. Status
Status message carries information about Controller’s status, input states and RF noise level. These
messages are requested by the Host every 30 seconds to confirm that the Controller is still present on the
bus and functioning properly. The Controller will send this message on its own if any parameter is changed
(as with any other message).
There are three data bytes in the Status message:
1. Noise Counter
Indicates number of times the Controller has detected signal on its receiver but that was not legitimate
data. The Controller is sampling receiver every 50 µs. This counter decrements over time (10 times
faster then it increments) if noise goes away. When the noise counter reaches 100, the Status message
is sent, and then again when the counter gets back to zero.
2. Input States
This byte describes the state of all inputs to the Controller as shown in the Table 6
Table 7 Input States
Bit Input Name Function
Bit 7 Not used
Bit 6 Strobe 0 – ignore other host inputs
1 – host inputs active (override, unlock, alarm)
Bit 5 Override 0 – override request
1 – no override request
Bit 4 Unlock 0 – lock release request
1 – no lock release request
Bit 3 Bypass key 1 – bypass key pressed
Bit 2 Reset key 1 – reset key pressed
Bit 1 Alarm 0 – host alarm request
1 – no host alarm request