Altec Lansing 4948A Contact Closure Connector, 5.4 RS-232 Dataport, AC Inlet and Power Switch

Operating Manual-4048A digital signal processor

5.3 Contact Closure Connector

There are no user controls on the 4048A, making it ideal for permanent installations where security is an issue. There may be times, however, where audio system adjustments must be made in response to real time acoustic changes, such as room size. For these types of changes, the 4048A offers the ability to recall up to eight different presets using contact closures. Contact closures are nothing more than external, user installed switches that, when closed, recall a previously defined preset which at once applies changes to the settings of all inputs and outputs. The switches can be anything from a rotary switch on a control room panel, to automatic door sensors located throughout a conference center, to a microphone key switch, etc. Contact closures allow for flexibility while maintaining a high degree of system security.

To use contact closure switching, up to eight presets (1-8) must first be defined according to the needs of the installation. Switches are to be configured so that closing the switch contact triggers the preset recall event. Either momentory or latching switches may be used, where the trigger event is the transition from open to closed for a given circuit. Closing a circuit will automatically override any previously recalled presets. Up to eight switches can be used, with all switches sharing a common ground connection. Each pin number above the contact closure connector corresponds to the number of the preset which will be recalled when that switch is closed. Always use the 4048A contact closure ground for contact closure switches. Do not connect the 4048A contact closure ground to any other external grounds, as ground loop currents may result.

5.4 RS-232 Dataport

The 4048A has two parallel RS-232 dataports, one on the front panel and one on the back, for connecting to a computer for software control. See section 6.3 for details on connecting to a computer.

5.5 AC Inlet and Power Switch

A detachable AC power cord is used on the 4048A. Since the internal universal power supply works from 80 to 260 VAC 50-60Hz, the only change necessary for use with international power is the appropriate AC power cord. The AC power switch is found on the back of the unit as well.

D-Sub 9 Pin Female

RS-232 Pin-Out

5 4 3 2 1

9 8 7 6

Pin # RS-232 DCE Name

1Not Connected

2Transmitted Data

3 Received Data

4 Data Terminal Ready (tied to pin 6)

5Ground

6Data Set Ready (tied to pin 4)

7 Not Connected

8 Not Connected

9 Not Connected

7