Philips SM30 Microphone Input Module MIM, Operation Remote Switching Function, Bass Cut Facility

8 MICROPHONE INPUT MODULE

(MIM) LBB 1282

Each Microphone Input Module allows two electret microphones or two dynamic microphones to be connected to the SM30 Control Centre.

SM30 will accept up to 3 Microphone Input Modules and/or Call Station Input Modules in total.

8.1Operation

Remote Switching Function

SM30 makes use of the remote switching facility of certain Philips electret microphones and dynamic microphones. This switch is used to activate calls originating from the microphone, including all of the programmed functions available (priority, routing, attention signals, etc.) (See chapter 14 for programming details).

Line Input Facility

By changing a switch, mounted on the circuit board of the module (one double switch block for each channel), it is possible to connect a line level input source, instead of a microphone. In its up position, switch 1 on the switch block is set for Microphone (the default). In its down position, it is set

switch block as the Line Input switch, the Bass Cut can be de-activated.

In its up position, switch 2 on the switch block is set for Bass Cut (the default). In its down position, it is set for Flat response.

8.2Installation

Mounting in the Control Centre

The Microphone Input Modules must be located in the Control Centre slots E, D, and/or C, as indicated in fig.5.1.

The number designated to a Microphone by the microprocessor is dependent on the slot in which the module is located.

If, for instance, only one Microphone Input Module is used in a system, and that module is located in slot E, then the two Microphones plugged into the module would be numbered 1 and 2.

If the same module were plugged into slot D, then the Microphones would be numbered 3 and 4.

If plugged into slot C, the Microphones would be numbered 5 and 6.

This regardless of the fact that they are the only Microphones in the system.

for Line Level Input. It is possible to distribute this line source by means of contacts on the Contact Input Module 1.

Bass Cut Facility

In noisy environments the operator often has to speak very close to the microphone, which exaggerates the bass frequencies of the microphone.

A bass-cut facility is available to reduce the bass, helping the call to be clearly heard. On delivery, the bass-cut is active. By

1

1

2

2

LBB 1282

2

1

1

4

2

1

Microphone

Line level

2 Microphone

	3
2	5	Remote on/off

1 2 Bass cut

Flat response Switch positions

changing switch 2, located on the same

Fig. 8 - MIM

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