3.2 Do Not Disturb and Lock
Enable DND: Press Menu → Access → "Lock/ND" → DND, the system prompts to enter personal password (default 0000) for confirmation. After activation, incoming calls will be intercepted by the system (can be converted to voicemail or busy tone).
Terminal Lock: prevents others from using the phone to dial out or modify configurations. Press the Lock key (if programmed) or enter Lock through the menu and enter the password. Unlock the same operation by entering the correct password.
3.3 Call Pickup
GrpPic: Used to connect ringing calls from other phones within the same group. Press the GrpPic key in programming or go to Menu → Access → "Call pickup services" → GrpPic.
Designated Relay (IndPic): Receive the ringtone of the designated extension. First press IndPic, then enter the target extension number.
Night service representative (NSBell): When the switchboard is unmanned, press NSBell to answer the night ringing.

Voice mailbox and message management
OmniPCX 4400 integrated voice mail system. The green LED flashing on Advanced REFLEXES indicates a new message or callback request.
Directly sending voice messages: In idle mode, press the Voice button (or go to the menu Access → "Voice mail services" → Voice) to enter the voice mailbox system, record the message according to the voice prompt, and send it to the designated extension.
Check messages: Press the flashing Message button (green LED), and the screen will display the total number of unread messages. Listen to voice messages one by one by pressing Read, or read text messages ("text messages" left by internal users).
Set up "Apology": When not seated, a text prompt can be set up for internal callers to view. Press Menu → Prog → Select "Apology", choose from preset templates such as "In a meeting" or "Back in a minute", or customize editing. After setting, any internal call to this phone will display the text on its screen.
Receipt and Call Back: For internal missed calls, the system will record up to 10 call records. Press the callback key to view the list and call back directly.
Multi party meetings and advanced call processing
5.1 Tripartite Conference
During a call, press the idle line key (LINE) to call the second party. After connecting, press Conf (if programmed) or select "Conference" from the menu to merge the two lines into a three-way call. The initiator can continue to add up to 6 parties (some systems have more restrictions), press AddOn to add new members one by one, and press Insert to merge the waiting party into the meeting.
5.2 Meet Me Conference
If the system configuration supports it, the administrator can preset a conference bridge and assign a secure access code. Participants can join by pressing MeetMe (or code) and entering the access code. Supports up to 29 parties (including initiators). External participants need to be transferred by internal users. Method: During the call, press LINE to dial the Meet Me access code, enter the security code, and then follow the transfer operation to send the external party into the meeting.
5.3 Barge In and Anti Strong Insertion
Authorized users can forcefully enter an ongoing internal call by pressing the BargeIn key (or code). The called party can enable "Privacy" in advance: press PrAgBn (or enable it through the menu), this function is only valid for the current call and automatically expires after hanging up.
5.4 Call Residency (Park)
External calls can be temporarily stored in the system and transferred to other phones for retrieval. Operation method: During the call, press Menu → Access → "Call pickup services" → Parked, enter the target extension number according to the voice prompt, and the call will be paused. Execute Parked on the target phone to retrieve it. If no target is specified, the system will automatically switch back to the switchboard after the timeout.
Daily troubleshooting and user self-service recovery
6.1 No display or inability to start the phone
Check if the Ethernet/telephone cables are loose and if the PoE power supply is working properly (if using a PoE switch).
If it is an independent power adapter, confirm that the adapter indicator light is normal.
Try unplugging the cable and wait for 10 seconds before powering it back on. If there is still no display, it may be a hardware failure. Contact the system administrator for replacement.
6.2 No response or inability to dial
Confirm that the phone is not in the "locked" state (Lock light is on). If it is locked, enter the password to unlock it.
Check if "Do Not Disturb" (DND) is enabled. If it is enabled, all incoming calls will be blocked, but they can be dialed out normally (DND does not affect dialing in some configurations).
If only external calls cannot be made, confirm if the correct external prefix (usually 9) is configured and check if the system restricts long-distance access to the phone.
6.3 Frequent disconnections or noise during calls
Firstly, eliminate poor contact in the physical circuit and re plug the handle cable and landline cable.