BSS BLU-101 Руководство по эксплуатации онлайн [8/12] 776408

Automatic Gain Control (AGC) and Noise Cancellation (NC) are also provided per AEC

algorithm. AGC ensures that microphone levels remain at an optimum level, and NC

removes steady state noise (such as from a projector fan or air conditioning device) from

the signal path.

Non-Linear Processing (NLP) dynamically adjusts to minimize echo caused by under or

over-cancellation.

CONTROL INPUTS

Used to connect switches or potentiometers, e.g. BLU-3 selector wallplate (Part no.

Z-BLU-3). Looking at the control port connector (on the back of the unit), there are two

common (ground) connections C to the left of the twelve CONTROL INPUTS and, two

software assignable reference voltage outputs R to the right.

The control ports have two modes of operation: 2-wire and 3-wire.

2-wire mode

In this mode the twelve CONTROL INPUTS are internally ‘pulled up’ to +5V DC via

a 4.7kOhm resistor. Therefore, no external voltage source is needed to create contact

closure to ground for switches such as mute buttons or, resistance to ground (for other

multi-state or continuous controls such as Parameter Presets or faders).

See the help file within HiQnet London Architect for a table of resistor values for use with

Parameter Presets or source selectors.

Two ‘common’ ground connections are provided using the two C connectors to the left of

the CONTROL INPUTS.

A 47kOhm-log potentiometer (Part no. DM10018) connected between a control input

and common will allow parameters to be controlled linearly.

3-wire mode

This mode allows the use of linear pots or faders for continuous controls. A pot would be

wired as a potential divider with the top of the track connected to the reference output

R, the wiper to a control input and the bottom of the track to a common C. For good

performance, pots with track resistance between 10K and 100KOhms are recommended.

LOGIC OUTPUTS

Used to connect ‘tally’ indicator LED’s or relays.

There are six standard LOGIC OUTPUTS which produce 0V or +5V DC via an internal

440 Ohm resistor and two internally connected common (ground) connections C.

An LED connected between one output (Anode, A) and common (Cathode, K) will

illuminate when the LOGIC OUTPUT is activated, without requiring any external current

limiting resistor.

A high sensitivity relay (such as a reed relay) may be driven by connecting four outputs in

parallel. This arrangement will develop 4V across a 500-Ohm coil, providing that all four

outputs are made logic 1 simultaneously.