5.1 Applying a Tolerance selecting a tolerance Applying a tolerance Tolerance testing Tolerance printing
Configuration T selects the tolerance to be applied, tolerances 1 to 10 being user
tolerances, while tolerances 11 to 20 are fixed. Configuration T0 disables tolerance
testing. Once configuration T has been set all sequence results will be automatically
checked against the tolerance whenever they are displayed. If testing domestic cassette
machines for example, it may be useful to set configuration T14 so that all results are
automatically compared against the Lindos Domestic Cassette tolerance.
Tolerance configuration
Tolerance selection
It is also possible to make a sequence select a particular tolerance to be applied. In this
case the tolerance number is specified within the sequence definition, in a ± segment (see
section 4.19), and this temporarily overrides the configuration T setting, until another
sequence is received, or until the LA102 configurations are edited.
± segment (select a tolerance)
If the tolerance is pre-defined in the LA102 (tolerances 10-20) then nothing else need be
done to check results against it. However, with user tolerances (1-10) the tolerance must
be defined and entered into the LA102, using a tolerance editor.
Because the tolerance check is performed at the time of display or printout (rather than as
the sequence is received) it is possible to change the tolerance number (configuration T)
at any time to check the results in memory against any of the available tolerances.
Similarly, it is possible to recall a results memory (
) to check it against the current
tolerance. Even examining a memory status (
) will perform a tolerance check on the
specified memory (see section 3.5 for details of memory operations).
5.2 Pre-Defined Tolerances Pre-defined tolerances Tolerance definitions
Tolerances 11-20 are pre-defined in the LA102 and cannot be changed. Tolerance 16 is
the Lindos Selftest tolerance which is normally automatically selected by sequence 16,
the Selftest sequence. The LA101 XLR outputs should be connected directly to the
LA102 XLR inputs using good, screened cable. The front jack sockets should not be used
because small errors in the output impedance can cause their own relatively large level
errors which are not included in the level accuracy specification of the LA101. Sequence
16 will set the LA101 test level and output impedance automatically, but 10k
input
impedance must be set on the LA102 before running the sequence.
Tolerances 17 to 20 are Engineering Performance Specifications (EPS) for programme
circuits used by British Telecom: EPS81 amplified 10kHz programme (sound) circuit for
mono transmission; EPS84 15kHz programme (sound) circuit suitable for mono
transmission; EPS98 10kHz mono multi-terminal programme circuit to connect a central
studio to a maximum of 12 outstations. Note that tolerance 18 applies to EPS84 circuits
less than 40km long while tolerance 19 applies to EPS84 circuits from 40 to 320km long.
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5. Tolerance Testing
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