LISA : Wireless embedded acquisition systems

Modular, rugged and flexible

LISA is a wireless acquisition system dedicated to analog parameters. It simplifies installation of on-ground or in-flight test systems by reducing wiring and power supply needs.

LISA is really modular and flexible : you can sample from 8 to hundreds of signals. Using a single or many radio links. It can co-operate with your existing test system or run as a self-sufficient, stand alone, acquisition equipment.

LISA is a perfect solution when wiring is difficult or even impossible. Helicopter rotors, moving parts, on-ground long distance transmission are typical examples of LISA applications.

Components

A LISA acquisition system is composed of, at least, one MACQ acquisition module. Two versions exist, 8 or 24 inputs. A MACQ module can be used alone, as an independent data logger, or connected to your existing acquisition system through an USB or a PCM link.

But a MACQ module can also be installed in a remote (or moving) part of your equipment and transmit its data through a pair of wireless emitter/receiver ER-800.

Several MACQ modules can be connected to a single receiver, thus sharing the bandwidth of the communication link.

Multiple pairs of emitters and receivers can also be used, increasing the throughput of the system.

Even when several radio links and acquisition modules are used, sampling of data is perfectly synchronous over the entire installation.

MACQ module versions

This compact acquisition module exists in 2 versions.

MACQ-862 supports 8 isochronous general purpose analog channels (voltage, strain gage, accelerometers and pt100) and can provide sensor excitation. Max sampling rate is 5 K sample per channel and per second.
MACQ-824 supports 24 isochronous analog inputs (thermocouples or voltages). Aggregated throughput is 32 K sample per second for each module.

Sampled data are time stamped and can be stored on a local removable storage. Simultaneously, they are transmitted both through a PCM output and an USB link. The three data flows use the same PCM format.

Other modules

When a wireless transmission is needed, the MACQ module will be connected to a wireless transmitter ER-800 which converts the PCM output into a signal received by another ER-800. Distance between emitter and receiver may reach 200 meters in open space. Effective transmission distance may vary with the choice of antennas and the aircraft environment. The receiving ER-800 rebuilds a PCM and an USB output.

These outputs can be connected to a computer or processed in a PCM concentrator such as CETH-800.

Optional battery modules such as BATT-848 or BATT-822 are sufficient for operations of 4 hours or more, depending on the sensor powering requirements. The MACQ may also be powered by an external 5 to 18 Vdc power supply.

The following figure describes several possible configurations in a LISA system.

Synchronization

Up to 8 parallel wireless connections are supported in a single installation (this may depend on local regulations on radio frequency usage). One of the receivers is configured as a master. It is able to forward current time and synchronize acquisitions on every MACQ module in the installation.

Data from every MACQ module are time-stamped with a unique clock transmitted by the master receiver. This clock can be controlled by an external IRIG B signal.

Configuration and Control

Configuration of analog signals is defined by switches on the MACQ module. Other configuration choices (time of the day, choice of master receiver…) are defined by a PC software through the USB port of ER-800 and MACQ modules.

Data acquisition can be started by a local switch on MACQ when used stand-alone or centralized (REM-800 hand held remote control box or computer software).

Software

ADAS provides configuration software on PC and a library and tools for real time data acquisition on a PC or off-line file management.