06/29/17
ICA-202D OPERATION AND INSTALLATION MANUAL
Page 22 of 32
The Reach is stepped with external controls;
Each momentary switch closure moves the setting by one step
There are 16 Levels, with 15 Steps in between
The "Up" control increases the "Reach" (Microphone Sensitivity) above the "Normal"
setting
The "Down" control decreases the "Reach"
The "Down" control has Auto-Repeat (If held for more than 1/2 second), and will return
to the "Normal" setting (One step at a time) at approximately 5 Steps/second
For PLC Applications:
The Quiescent input is an Open Circuit (Pulled internally to +6 Volts)
One Input or the other should be momentarily pulled to Common, never both at the same time
The Active (Low level) should be held 100 to 250 mS
The rest (Open Circuit) between pulses should be greater than 200mS
The "Down" Input has an Auto-Repeat function, so the "Reach" may be reset to the "Normal"
setting by holding the "Down" input Active (Low level) for 4 Seconds.
There are three configurations of these controls that have practical applications:
1. The "External Stepped Reach Control" is not used
When the ICA-202D-3 first powers up, the "External Extended Reach Control" is set to
"minimum"
gain of 0dB
This essentially puts the "External Stepped Control" out of the circuit
Therefore the front panel Rotary "Reach Control" has the entire range of 45dB; 3dB/step
2. Both the "External Stepped Reach Control" and the Rotary "Reach" Switch are used
The standard setup is to set the Rotary "Reach Switch" to a "normal setting", the onset
of limiting for a 'normal' speaking level at the Remote Station
With the "External (Extended) Stepped Reach Control", set to "minimum" of 0dB
As the "External Reach Control" ("minimum" gain) is advanced,
the remainder of the 45dB of gain is divided into the 16 steps
As an example, consider a setup where the Rotary Switch is set to "12 O'clock", which
represents a microphone gain of ~24dB
The remainder of the gain (24dB) is controlled by the "Extended External Stepped
Reach Control" with 1.5dB/step
In this configuration, the Rotary Switch should never be set past the 3 O'clock position
Otherwise, very little control is available to the External Control.
3. Only the "External Stepped Reach Control" is used by an external controller PLC
The setting of the Rotary "Reach" Switch is set to "0", (Red dot, at 6 O'clock position)
Then the "External Stepped Reach Control" has the entire range, 45dB; 3dB/step
Under most conditions it is recommended when using a PLC, setup '2' is used
