14
M4FM-HD User Manual
System Menu
Press and hold the CENTER button for 3 seconds to enter the SYSTEM menu. Use the arrow buttons
to navigate to the desired submenu. To exit to the previous menu enter selection mode and toggle the
arrow up to EXIT and press the CENTER button to revert back to the previous screen.
Figure 9.
Audio Muting
- The M4FM-HD’s audio output can be set to automatically mute for received signals
with signal strength less than 45dBf.
Forcing A-D Split –
using headphones this feature puts the Digital signal in the
left ear and the Analog in the right ear. Enabling SPLIT mode will disable all
tuning until SPLIT mode is disabled.
Alarms
Program Loss Monitor –
Enabling any alarm will disable tuning, presets and band selection from the
WebServer and M4FM-HD box User interface.
Program Loss Monitor (PLM) Connections –
The PLM provides six dry, floating relays with outputs
on a rear panel mounted DB15 connector to report selected alarm conditions, including loss of RF
carrier, audio loss, OFDM Lock Loss, HD Lock Loss, Multicast Loss, and Over Modulation. Opto-
isolated inputs will be triggered by a voltage of 5VDC. The GPIO Alarm output relays are Normally
Open and will close when an alarm is active. See figure 10 for the DB15 pin-outs:
Alarm Loss of:
No Contact
Common
Audio
5
10
RF Carrier
4
9
OFDM Lock Loss
3
8
HD Lock Loss
2
7
Multicast Loss
1
6
Over Modulation
11
12
Reset
14
15
Pin 13 is not used
Figure 10.