Chiron Technology IRIS 8xx Series Przewodnik Instalacji Pobierz pdf (Strona 24)

Iris Management Suite

Technical Guide V1.7C 4/11/07

8 Polling Overdue Detection and Action

The Polling Engine expects each remote IRIS dialler to poll in at the time

interval specified within the database loaded from the Console. If a poll is not

received, the Polling Engine reports this as a Poll Overdue to the ARC.

When polls are again received, the Polling Engine reports a Poll OK to the

ARC.

The ARC therefore only sees state changes and is not inundated with

messages.

The Polling Engine makes allowance for the fact that a poll may be delayed,

and allows extra time margin over the polling period, before reporting

overdue. This extra margin allows for such things as transient network delays,

longer delays if the polling is over GPRS, or delays because the Polling

Engine is a Backup for the IRIS dialler which first times out while trying its

Main Polling Engine.

The amount of margin can be set as a system wide parameter on the

Console.

The way this operates is as follows:

• For shorter polling periods, the margin is a proportion of the polling

period.

• For longer polling periods, the margin is a fixed period, as a percentage

would give unnecessarily large overdue reporting times.

The threshold between these actions can also be changed. If the poll period is

less than the threshold, the percentage is used. If the poll period is greater or

equal to the threshold, the fixed time is used.

It is recommended that a typical setting for high security systems is a 60s poll

with margin of 100%. This means that any communications problem with the

remote alarm system will be reported in 120s, which is well within the 180s

required with the EN 50131 standards for the highest security grade (Grade

4).

1 2 ... 19 20 21 22 23 24 25 26 27 28 29 ... 36 37

Brak uwag

Chiron Technology IRIS 8xx Series Przewodnik Instalacji Strona 24