ANSI TIA 470.220 E pdf free download

ANSI TIA 470.220 E pdf free download.Telecommunications Telephone Terminal Equipment Alerter Acoustic Output Performance Requirements for Analog Telephones.
4 TESTING CONS1DERA TIONS
Alerters provide an acoustic output in response to ringing signals supplied to the device in the On-Hook
State. The following requirements are intended to cover the response of alerters for
Type-A ringing signals as identified in TIA-968-B.
4.1 TEST EQUIPMENT PERFORMANCE
The ring generator in the various test circuits shall be capable of generating the applicable test signals.
The source impedance shall he lower than 900 ohms and should he lower than 6(X) ohms.
The test circuit shall use a true RMS Voltmeter.
4.2 TEST METHODS
Several performance measurement procedures are established, each of which yields standardized measurement data that may be used for the determination of compliance with this standard. Although this document may reference specific procedures or test equipment, the intent is not to be all-inclusive. Any measurement procedure and equipment that can result in an identical measurement is considered valid.
Note: If the main purpose for testing to this standard is comparison testing of different products, rather than compliance testing, then it is important that identical test procedures and equipment be used when testing the different products.
While the procedures may call out specific test points within the requirements. the full range of the requirements take precedence.
4.3 SAFETY
This standard does not contain safety requirements. Compliance with the applicable UL and CSA safety standards may he required in certain locations.
S TECHNICAL REQUIREMENTS
5.1 CATEGORIEs OF CRITERIA
Three types of requirements are specified in this standard: Mandatory, Recommended and Permissive:
1. Mandatory requirements are designated by the terms “shall” and “shall not”. These requirements are used to indicate conformity in which no deviation is permitted.
2. Recommended requirements are designated by the terms “should” and “should not”. These requirements generally relate to compatibility or performance advantages towards which future designs should strive.
3. Permissive requirements are designated by the terms “may” and “may not”. These requirements are used to indicate an action that is permitted within the limits of the standard.
5.2 AI:Ri’ER SENsn’IvrI’’
5.2.1 Response to Ringing Signals
5.2.1.1 Requirement
The alerter shall audibly respond to the range of ringing signal frequencies and voltages given in Table I.
Note: The network ringing signal may not he a sine wave. ATIS-060040l.2006 indicates the crest factor of the ringing signal shall be between 1.2 and 1.6 and should he between 1.35 and 1.45.
5.2.1.2 Method of Measurement
I. Connect the DUT to the test circuit shown in Figure 1 and, for each test signal in Table 2, determine if the DUT provides an acoustic alerting response.
2. Repeat for the opposite dc polarity.
5.2.2 Reproduction of I)istinctive Ringing Patterns
The mandatory requirements in this clause insure that a single device audibly reproduces the distinctive ringing patterns. The recommended requirements in this clause are provided to improve the audible synchronization of multiple devices to distinctive ringing patterns.
5.2.2.1 Ringing Cycle
A ringing cycle consists of the lollowing components:
I. One or more On Periods.
2. Zero, one, or more Off Periods.
3. Long Silent Interval (LSI) period, which follows the last On Period.
5.2.2.2 Requirements
For at least one user selectable setting. the device shall meet the applicable requirements below in response to each of the ringing patterns described in Table 3 (patterns I through 5) using the listed nominal duration times.
Note: A more robust device will also meet the requirements below using the minimum and maximum duration times listed in Table 3.
I. All devices, except cordless handsets:
• Shall audibly reproduce the ringing pattern signals in Table 3 without missing or combining On
Periods.
• Should produce an audible alerting response within 150 ms from the start of each On Period
applied to Tip and Ring.
• Should end audible alerting within 150 rns from the end of each On Period.ANSI TIA 470.220 E pdf download.