SC4x0 Technical manual
Page 22 of 34
SeaCom
Rev
2.00
Full volume is not always practical or applicable. Therefore an absolute max volume for PA call can be
set from the hidden menu.
9.9 External speaker
The external speaker can be programmed to be on by default. It has an 1.5sec lead time delay
meaning
the first ring will only be in the local speaker.
If programmed to be on, hands free will use the external speaker by default It can always be turned on
or off manually.
9.10 Adjusting external dimmer input
When the unit is tested & shipped, it is ensured that full range can be obtained. However, an input
voltage of 28 may not give 100% brightness and 5 volt will not give 0%.
The input needs to be calibrated to the actual zero- and full-scale output from the central dimmer.
To calibrate the input, set the dimmer to zero or approx 5 volt. Go to the hidden menu and read out the
dimmer input value. Note it for later use.
Set the dimmer to max output and read out the dimmer input value from the hidden menu.
Use the following formula to calculate offset and gain factor.
A
Offset
= Dimmer input value in % at 5 volt.
A
Gain
= 100 / (Dimmer input value in % at max - Dimmer input value in % at 5 volt)
The values for A
Offset
& A
Gain
can be entered via set parameter xx.
After entering these values, backlight level should be approx 0% at 5 volt and 100% at max.
NOTE: Extern dimmer are optionally and require additional hardware.
9.11 Local external microphone
If a remote microphone is required to work in conjunction with local or external speaker, select this
option from the setup menu level 3.
The external microphone is selected by use of a switch connected to the headset PTT input.
This mode can be used to extend the operation of the telephone from another physical location e.g.
control desk.
The local push button is operated as if the phone was in local PTT mode using the PTT (mic) button.
