DAQ Application: Fiber Optic Testing | GaGe

Test & Measurement Application Case Study - Data Acquisition Electronics / Device Testing

Test & Measurement Applications

Fiber Optic Automated Measurement System

Customer Case

The customer is in the business of developing lasers and LED components for fiber optic data \ telecommunications applications. The requirement is for an automated test system to monitor the pulse characteristics of the laser.

The customer will require 3 channels at high vertical resolution due to the fact that some variances in amplitude will be only 1 mV and need to be detected. The goal is to capture 10,000 samples per channel at 50 MegaSamples per second with a 1 KHz to 5 KHz Pulse Repeat Frequency (PRF). The customer would like to develop a software interface in the LabVIEW environment.

GaGe Case Solution

The CompuScope 14100 14-bit 100 MS/s A/D and Scope Card for the PCI Bus in a Master\Slave configuration is ideal for the requirement. GaGe specializes in configuring multiple boards as Master and Slaves providing true simultaneous sampling on all channels. Aided by proprietary Bridge Board technology, GaGe assures simultaneous sampling with the Slave(s) receiving their clock and trigger signals from the Master. The PCI Bus Mastering capabilities will aid in obtaining the desired PRF.

Simultaneously capturing on 3 channels at 50 MS/s will fulfill the requirement. 14-bit vertical resolution aids in detecting the 1 mV variances, although an amplifier is recommended before the inputs. Capturing 10,000 samples with these parameters gives a total capture time of 200 microseconds, transfer time of 600 m s, and rearm time of 90ms (30ms per channel) for a PRF of 890ms or ~ 1.2 KHz. Similarly, at 5,000 points the PRF is ~ 2.9 KHz. This is acceptable for the customer's application as he will not always take 3 channels and the number of samples to be captured is still to be determined at this stage.

We should note that, strictly speaking, the above-calculated PRF capabilities of the CS14100 apply only in the single-tasking DOS environment. Window's multi-tasking and LabVIEW's high-level subroutine calls will somewhat lower these rates. If the card is not capable of keeping up with the required PRF in Single Record mode, then Multiple Record can be used. In this mode, the CS14100 is re-armed almost instantaneously in hardware with no CPU intervention required. Consequently, the operation is deterministic and no triggers will be missed.

The CompuScope LabVIEW Software Development Kit is recommended for development. The LabVIEW SDK is supplied with many Sample VIs to get developers started. These VIs demonstrate different functions of GaGe cards and can easily be combined for a robust application. Front Panel GUI's are included, thus cutting down required programming development time. All GaGe CompuScope SDK's are supplied with the Standard Edition of GaGeScope PC Oscilloscope Software, a Windows-based application program. The Professional Edition of GaGeScope contains enhanced acquisition and analysis features.

GaGe Case Recommended Products

Test & Measurement Application Request

We encourage you to contact us and discuss your test & measurement application in more detail with our engineering team. GaGe can provide tailored custom data acquisition hardware and software solutions to meet specific application requirements.