Euro standards in close-up | Archive Titles

Table 1 – Transmission time classification
	Transmission time (seconds)
Class	D0	D1	D2	D3	D4
Arithmetic mean of all transmissions	-	120	60	20	10
95% of all transmissions	240	240	80	30	15
Table 1 represents the time in seconds for the arithmetic average of all transmissions and the corresponding percentage of all transmission times.

Table 2 – Transmission time, maximum values
	Maximum time (seconds)
Class	M0	M1	M2	M3	M4
Maximum acceptable Transmission time	-	480	120	60	20
Table 2 represents the maximum time, in seconds, for the transmission system to signal through to the monitoring centre. Any time exceeding the maximum acceptable time for a specific system for each incident will be classified as a transmission fault. The transmission time is measured from the time that a change occurs at the supervised premises transceiver to the alarm system; to the time that the new state is reported at the receiving centre interface to the annunciation equipment. The transmission time applies to all changes of state that are transmitted from the alarm system through to the supervised premises transceiver interface to the alarm transmission system.

Table 3 – Reporting time classification
	Reporting time
Class	T1 days	T2 hour	T3 min	T4 sec	T5 sec
Maximum Period	32	25	300	180	90
Table 3 represents, for systems with automatic monitoring, the period from when a fault occurs in the alarm transmission system until the fault is reported to the alarm receiving centre and/or monitoring centre e.g. by the failure of the monitoring centre to receive the reporting signal.

Table 4 – Availability classification
	Availability
Class	A0	A1 %	A2 %	A3 %	A4 %
Availability of overall system in any 12 month period	No req	97	99.3	99.5	99.8
Monthly availability	No req	75	91	95	98.5
Table 4 represents the availability of an alarm transmission system. The availability of the transmission system should not be less than the percentage indicated. Details of how to calculate availability are included in EN 50136.1.1