Polarization Voltage; Manual, Interface And Pc Control - BRUEL & KJAER 5998 Service Manual

Chapter 5 — Theory of Operation
Functional Description
1. Set all instruments to power off before changing their ground connections.
2. Connect the Signal Ground lines of all instruments together. This is done auto-
Warning: Type 5998 is designed to be operated with its signal ground, output
ground and chassis at zero earth potential. Internal protection diodes limit the
maximum potential difference between the chassis and the signal ground to 0.1 V.
Never let the ground terminals, socket screens or chassis float at other than ap-
proximately zero earth potential, as this may damage the Reciprocity Apparatus.
5.2.2

Polarization Voltage

Before connecting microphones/preamplifiers to the preamplifier input sockets
(front panel), ensure that the polarization voltage switches corresponding to the
channels to be used are set to the correct voltage. The correct polarization voltage
is indicated on the calibration chart of the microphone.
5.2.3

Manual, Interface and PC Control

Manual Control
When you switch Type 5998 on, it is in local mode and can be controlled manually.
See
controls.
If the Remote LED is lit, Type 5998 cannot be controlled manually. Press <Local>
to regain manual control.
Control via the IEEE –488 Interface
Type 5998 is a basic listening device conforming to IEEE–488.2 which can be con-
trolled via the IEEE–488 bus. The interface is compatible with IEC 625–1. You can
thus use a PC equipped with a National Instruments IEEE card to control the
apparatus for remote operation.
Interface Functions Implemented
The subsets of the interface functions implemented are listed in
also includes the corresponding IEEE/ANSI and IEC sections and clauses:
Setting the Device Address
Type 5998 uses one listener address. This is set to 20 (decimal) on delivery from
Brüel & Kjær and will normally not need to be changed.
5 − 4
matically through the screens of the input and output cables used to intercon-
nect the instruments
section 1.5.1 and section 1.5.2
Reciprocity Calibration Apparatus Type 5998
for a description of the front and back panel
Service Manual
Table 5.1, which
Brüel & Kjær