Lab.gruppen PLM 20000Q - Manual (Page 89)

Appendix
83
PLM Series Operation Manual rev 1.2.3
Term Description
Floating
An analog balanced input or output is said to be floating when full electrical isolation exists between that input or output and the
equipment connected to it. Transformer-coupled inputs and outputs are inherently floating. Electronically balanced inputs and outputs
can never be truly floating, though better designs – such as that found in the PLM - do mimic the characteristics of transformer-coupled
designs to a high degree.
Frame Lake terminology for a physical unit containing a Lake processing system, i.e. a single LM 26, PLM or legacy Lake Processor.
Frame ID An electronic identification ‘label’ which can be given to each Frame in an amplification system. Naming Frames in a large system is
desirable as it simplifies identification in the Lake Controller.
Frame Preset Frame Presets are a class of Presets within the Lake processing system. Up to 100 can be stored in the hardware device, and each holds
the complete configuration of all Modules and the Modules’ internal settings.
Gigabit Ethernet Describes the speed of Ethernet data transfer for devices that transmit Ethernet frames at a rate of a gigabit per second, as defined by
the IEEE 802.3-2008 standard.
Hub A type of network interface device with multiple Ethernet ports. Data arriving at any port is sent to all others. Hubs have been largely
replaced by Switches.
In-Rush Current
When power is applied to a piece of electronic equipment, the initial current taken by the PSU can be very high as the various capacitors
in the circuitry charge up; this is called the in-rush current. In the case of power amplifiers, which contain numerous very large
capacitors, the in-rush current can be enough to blow mains breakers. The PLM’s PSU contains circuitry to control the in-rush current to
prevent this.
Input Level
The amplitude of an audio signal at the point where it is applied to the input of the device, or at the input of an intermediate stage within
it. An analog input signal level will be expressed in dBu’s, while a digital input signal level in dBfS (dBs below digital clip level; fS =
full-scale)
IP Address
Every item of equipment connected to an Ethernet network has a unique address called the IP address, so that data gets to the correct
place. IP addresses are written as four groups of three decimal numbers between 0 and 255. In a system consisting of Lake Processors
and a Lake Controller they are assigned and detected automatically.
IP Subnet Mask IP subnet masks are required in all IP networks. The subnet is determined by the size and type of network being used. For small
networks (less than 254 addresses) a subnet mask of 255.255.255.0 can be used. (A Class C network).
Iso-Float Iso-Float is Lake’s proprietary method of electronic balancing, which provides a particularly high level of isolation and immunity from
ground loops.
ISVPL
ISVPL is an abbreviation for Inter-Sample Voltage Peak Limiter, a proprietary Lab.gruppen technique for ensuring that voltage at the
output terminals of a PLM does not exceed a pre-determined level. Eight ISVPL profiles provide the ability to configure for low distortion
or high SPL specific to certain frequency ranges, or for universal use.
Lake Controller
The Lake Controller is the software application used to control LM 26 Processors, PLM Series and other Lake devices. This software
application provides additional functionality and allows various grouping functions for simultaneous control of multiple Lake Processing-
enabled devices.
Latency
The small but finite delay incurred by audio signals when they are transformed into the digital domain, processed digitally and then
converted back into analog signals. In the Lake system, latency is assured to be constant.
Legacy Lake Device
This term refers to older Lake audio equipment which may form part of an audio system (i.e. Lake Contour Pro 26, Lake Mesa Quad EQ
and the Dolby Lake Processor). The Lake Controller has the capability to control all Lake legacy products.
LimiterMax LimiterMax is the name given to Lake’s proprietary package of dynamics control which forms part of the Lake Processing system.
Line Driver
An analog audio amplifier, usually with zero gain, having very low output impedance and high drive capability. They are used for
transmitting balanced analog audio over very long cables.
Linear Phase Crossover See FIR Filters.
Load Library
The Lake Controller includes LoadLibrary, a set of Module files specific to the PLM Series. These Modules include a database of the
electrical characteristics of various popular loudspeakers in addition to the standard Module data. The PLM uses the load data when
verifying and monitoring amplifier loads. See Fingerprint, LoadSmart and SpeakerSafe.
Load, equal/unequal The PLM draws different current levels from the AC supply, and thus has different power ratings according to whether all channels of the
amplifier are driving into the same load impedance, or if there are different impedances on different channels.
LoadSmart LoadSmart is a load verification procedure within the PLM which allows the operator to confirm that each PLM output has the correct
quantity and type of speaker connected to it. It is intended to be used pre-performance prior to running SpeakerSafe.
Loop-Thru This term refers to the Link connectors provided on the PLM for daisy-chaining further amplifiers or other equipment. The use of these
to connect further devices is termed a loop-thru.
MAC Address In addition to an IP address, every device on an Ethernet network has a MAC address. This address is fixed at the time of manufacture,
and is effectively the permanent identifier of the physical unit. MAC stands for Media Access Control
MaxPeak Lake’s LimiterMax provides independent dynamics control over signal peaks (MaxPeak) and the average signal level (MaxRMS).
MaxRMS See MaxPeak.
Module
Module is the term used in the Lake Controller to describe the virtual set of signal processing that routes an audio input to the various
frequency-weighted outputs of a crossover. The processing system within the device allows for two Modules, each of which may be
assigned a range of crossover configurations, input sources, etc.
Module Preset
A class of Preset within the Lake processing system. A Module Preset (Module file) contains all the configuration data and settings for
one Module, and is saved in the Lake Controller software, not in the hardware device.
Offline
A device on an Ethernet network which is not communicating with the rest of the network either due to a fault or intentionally is said to
be offline.
Online A device on an Ethernet network which is fully operational and communicating with the rest of the network is said to be online.