Specialists in Mechanical Testing and Reliability of Optical Fibers

Trigger Box Monitor

For Fiber Fracture Logging

Purpose

The fracture of high strength silica optical fiber, as well as weaker materials, may be conveniently detected in static or dynamic fatigue experiments by the associated acoustic emission [ref. 1]. The Four Channel Trigger Box, supplied by Fiber Sigma, accepts the signals from four acoustic transducers and produces a TTL pulse for each fracture detected. The Trigger Box Monitor system is designed to connect to up to 8 or 16 Trigger Boxes and, via software running on an IBM PC or compatible, logs when fiber breaks occur. The software features fine timing resolution (~ 1 ms) on up to (4 ´ 16) 64 channels, statistical analysis of results (including prediction of results of incomplete experiments) and automatic recovery from power supply failures.

Description

The basic Trigger Box Monitor system comprises an interface unit that connects to up to 8 Fiber Sigma Trigger Boxes. The interface monitors not only the digital signals from each trigger box, but also the power supply status of each trigger box. All inputs are latched and optically isolated for noise immunity. The interface unit connects to an interface card installed in a PC. Up to 2 interface units (and potentially more) can be connected simultaneously giving up to 64 channels being monitored simultaneously. Control software monitors the status of active channels, logs the times of fracture events. It also performs complete statistical analysis of results, including the capability to analyze censored data, i.e. the results of experiments can be predicted while they are still in progress. The entire system is designed to recover from errors, such as power failures, with the minimum loss of information. The system has the following features:

	optically isolated and latched inputs from Trigger Boxes.
	monitors Trigger Box power status - logging any periods of power loss.
	sub millisecond resolution of event recording.
	experiment durations of up to decades are supported (no bugs associated with dates after 1999 – Y2K compliant).
	automatic compensation for summer time/daylight savings time changes for many regions of the world.
	screen automatically is blanked during periods of inactivity to avoid damaging the screen phosphor.
	built-in data manipulation including viewing, editing, graphing, analysis and export.
	built-in statistical analysis of data (normal, log normal, unbiased Weibull, percentiles etc.).
	on-screen Weibull plot of data.
	analysis of censored data (events inside or outside a range, before of after) permits results prediction (with confidence intervals) for experiments in progress.
	analysis results are compatible with applicable Bellcore/Telcordia requirements and relevant EIA/TIA and IEC test procedures.
	export of data in ASCII format compatible with all major spreadsheet and graphics programs.
	user-friendly full-color menu system for software control.
	interrupt driven, PC can be used to copy, analyze, plot data etc. without missing events.
	software interrupts (not hardware) avoid incompatibility with other computer hardware (sound cards etc.).
	includes all necessary cables and connectors: trigger box cables supplied are one each of 1 m and 6 m, two each of 2, 3, 4 and 5 m.

Other Requirements

The minimum computer system required for operating the Trigger Box Monitor system is a PC with an Intel 80286 processor or higher. The computer should have at least one free ISA expansion slot and at least 2 Mbytes of hard disc space. The computer should be running DOS, Windows 95 or Windows 98/98SE.

Control software and an event logging system for Windows-based PCs is currently in development.

An uninterruptible power supply for the computer and trigger boxes is strongly recommended.

Ordering Information

Description	Part #
Trigger Box Monitor (32 Channels)	TBM-8
Additional 32 Channel Interface Units	TBM-8A
Additional Trigger Box Cables (x meters)	TBM-Cx

References

M. J. Matthewson & C. R. Kurkjian, "Static fatigue of optical fibers in bending", J. Am. Ceram. Soc. 70 [9] 662-668 (1987).