Data sheet, 4lsl – Procom 4LSL User Manual

Page 4

Data Sheet

4LSL

Loudspeaker Function Card

Function Description:

The following functions are available on the 4LSL:

Monitoring of Impedance

New installations or changes in a loudspeaker circuit are monitored for changes
in impedance behaviour with the help of the 4LSL module.

For this the installed and manually tested loudspeaker circuit is measured with
the 4LSL module and its impedance is determined. The reference signal (125
Hz audio signal)

required for this is generated and made available by a differ-

ent module (TG01).

Set 1 of 4

Msgmt.

Circuit

Loudspeaker Circuit

Schematic illustration of impedance monitoring

Measurement of the connected loudspeaker circuit is automatic. For this the au-
dio signal generator is tested for proper functionality as well as the loudspeaker
circuit for falling short of the minimum loudspeaker load and exceeding of the
maximum loudspeaker load (load >= 2.5 W or <= 150 W). If the audio signal
generator is not working properly (audio signal monitoring), or if the load of the
connected loudspeakers is outside the indicated limits then this is indicated by the
LED and system messages. Re-measuring is then automatically prevented. Re-
measuring only becomes possible with a proper basic measurement.

Date:

13.03.2009 Page:

4/7 Author:

Document-No.:

DB_4LSL_2830_01