Features & Configuration
| Long Line Public Address Features & Configuration |
Queensgate offers an advanced Digital LLPA system called the LLPA (Long Line Public Address). Example features and components are demonstrated below.
LLPA
The system is modular and comprises MPU's (microprocessor units consisting of PC's) at each outstation connected by modems controlled by one or more user terminals.
Messages are created in the user terminal, compressed and transmitted to each or all outstations as required. The outstation decompresses and plays through a sound card.
Features (subject to options taken) include digitised speech for low loss, auto alternate path communications, pre-recorded announcement compilation, etc.
VoIP
With modern advances in Broadband technology, speed, and low costs, it is now the ideal method of connecting computer systems over long distances.
Previous limitations of leased lines and modem connections can be forgotten, but are still available in situations where broadband in not available.
LAN and WAN networks are also very suitable for both LLPA and VoIP services.
LLPA Equipment
SCIS (PC)
Used at outstations and can also
be used as a User Interface.See the data sheet for full details.
Modems
Used when a WAN/LAN or Internet service is not available.
- Voice/fax modems are often the most reliable.
- Most have a low power external power supply.
- Carrier, Send, Receive indication by red LED.
- Connection, standard PSTN socket.
ZoneR (Zone Router)
A ZoneR controller is used in preference to the ZoneC when there is an IP (LAN) connection available.
See the Data Sheet for further information.
ZoneC (Zone Controller)
A ZoneC controller is used when there is not an IP connection available between the outstation and the control room PC.
See the Data Sheet for further information.
- Dimensions: 185mm x 185mm x 100mm (Depth, Width, Height).
Please provide at least 300mm x 200mm x 100mm to allow for cable entry and connectors.- 1V Peak to Peak audio, balanced at 600 ohms.
- Output control switching and Audio out by block screw terminal.
- Outputs dry switched for 24V DC or AC at max current of 50mA. Outputs must be protected from back EMF arising from inductive loads. Normally off or normally on contacts selectable by screw terminal (SPDT reed relay).
- Switched outputs include 1 output per zone (where option taken) and 1 overall relay (SPDT reed relay) for amplifier selection. The latter relay always operates during DRA announcement regardless of zone selection and is intended for amplifier picking where necessary.
- Mic input switching (for system detection of local user contention) - dry switch contact capable of switching 5V to 10V at 100mA with line and contact impedance not to exceed 20 ohms. (Operates a relay coil with back EMF dissipation fitted).
- Mic interruption causes abortion of current message. Central user is notified. Message is not queued as this would prohibit local users from aborting the message. The central user must therefore relaunch the message if interrupted or if started while remote user has control.
- Mic priority set by host PA amplifier (circuitry for this not included). Mic priority is expected to be to remote user.
- Heat Dissipation negligible.
System
Microphones are normally supplied with a pre-amp.
See the Data Sheet for further details.QSL normally supply a small pre-amp that has proved
very efficient and reliable.
See the Data Sheet for further details.
- System usage type: Mouse, Keyboard and Microphone PTT.
- Data transmission type: Compressed digitised speech using up to 19.2KBd bandwidth (where both data paths active).
- Out-station polling and response at a frequency of 1 minute or greater. Loop integrity check included.
- VDU: The operator screen(s) indicate the following functionality -
- Message is being broadcast at out-station
- Local microphone in operation
- Last message sent (by time) and if message broadcast
- Out-station failure and where
- Loop test failure and where
- Operation:
- Stations and Zones Main Menu: Selection of station(s) and zones by mouse or keyboard
- Message Sub Menu: Allows recording and storing of messages, selection of messages from a list, message review, message management (copy, rename, etc).
- Fault log Menu: Allows revision of faults and technical detail.
- Options for Manual or Automatically Compiled messages.
Note:
Images and specifications are typical and particular equipment shown may be replaced by other similar equipment. All specifications subject to options purchased and subject to change. RLLPA is a trademark for the Queensgate Systems component of DLLPA. Note that among other exclusions, amplifiers, outstation microphones and speakers are excluded. QSL Terms apply.
