Persistent Link:
http://hdl.handle.net/10150/608382
Title:
“DATA DIGITIZING UNIT” ELIMINATES THE NEED FOR ANALOG RECORDERS
Author:
Bougan, Timothy B.
Affiliation:
Science Applications International Corporation
Issue Date:
1996-10
Rights:
Copyright © International Foundation for Telemetering
Collection Information:
Proceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection.
Publisher:
International Foundation for Telemetering
Journal:
International Telemetering Conference Proceedings
Abstract:
Today’s telemetry environment is becoming increasingly digital. Highly reliable and relatively inexpensive digital recorders readily available, and most telemetry facilities are migrating away from the older analog recorders which are difficult to calibrate and expensive to maintain. Unfortunately, most site managers find they still have one or more “legacy” signals (such as FM-FM, PAM, and pre-detect PCM) that still require analog recording. To exclusively use digital recorders the TM site must integrate some device to convert the analog signals to digital format before recording. Until recently, the TM site managers had very few options short of building custom equipment to convert and capture the legacy signals. One solution available from Racal (for their Storeplex digital recorder) is to purchase their Analog Record/Play Signal Module. Unfortunately, their module uses a 16-bit Sigma-Delta converter and has a maximum bandwidth of 45.5 KHz, which is woefully inadequate for many analog signals. Other manufacturers offer similar solutions with similar bandwidth restrictions. Another solution is to purchase a multiplexor “front-end” which is capable of mixing multiple signal types (both digital and analog) on to the recorder’s serial-digital data stream. This option can provide higher analog bandwidths, but represents a significant investment (greater than $100K and often more than the recorder itself). This paper discusses the conceptualization, design, and performance of a unit to fill the gap between the low-bandwidth analog channel module and the high-end signal multiplexors. We will discuss how high-speed field-programmable gate arrays (FPGAs) can be configured to provide a low-cost interface between the digital recorder and the analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) to capture and playback the analog signals. Our design focuses on achieving the maximum possible bandwidth for each analog signal while ensuring that IRIG-A or IRIG-B timecode are recorded simultaneously (so the analog signals can be later synchronized with their digital counterparts). We have found that such a solution permits multiple analog signals from 400 KHz up to 3 MHz to be easily and inexpensively recorded on the current generation of digital recorders. Our conclusions show that such a device can permit most telemetry sites to transition completely to more reliable, cheaper, and easier-to-maintain digital recorders.
Keywords:
Recorders; Digital Recorders; Multiplexors; A/D Conversion; D/A Conversion; PCM; PAM; FM-FM
Sponsors:
International Foundation for Telemetering
ISSN:
0884-5123; 0074-9079
Additional Links:
http://www.telemetry.org/

Full metadata record

DC FieldValue Language
dc.language.isoen_USen
dc.title“DATA DIGITIZING UNIT” ELIMINATES THE NEED FOR ANALOG RECORDERSen_US
dc.contributor.authorBougan, Timothy B.en
dc.contributor.departmentScience Applications International Corporationen
dc.date.issued1996-10en
dc.rightsCopyright © International Foundation for Telemeteringen
dc.description.collectioninformationProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection.en
dc.publisherInternational Foundation for Telemeteringen
dc.description.abstractToday’s telemetry environment is becoming increasingly digital. Highly reliable and relatively inexpensive digital recorders readily available, and most telemetry facilities are migrating away from the older analog recorders which are difficult to calibrate and expensive to maintain. Unfortunately, most site managers find they still have one or more “legacy” signals (such as FM-FM, PAM, and pre-detect PCM) that still require analog recording. To exclusively use digital recorders the TM site must integrate some device to convert the analog signals to digital format before recording. Until recently, the TM site managers had very few options short of building custom equipment to convert and capture the legacy signals. One solution available from Racal (for their Storeplex digital recorder) is to purchase their Analog Record/Play Signal Module. Unfortunately, their module uses a 16-bit Sigma-Delta converter and has a maximum bandwidth of 45.5 KHz, which is woefully inadequate for many analog signals. Other manufacturers offer similar solutions with similar bandwidth restrictions. Another solution is to purchase a multiplexor “front-end” which is capable of mixing multiple signal types (both digital and analog) on to the recorder’s serial-digital data stream. This option can provide higher analog bandwidths, but represents a significant investment (greater than $100K and often more than the recorder itself). This paper discusses the conceptualization, design, and performance of a unit to fill the gap between the low-bandwidth analog channel module and the high-end signal multiplexors. We will discuss how high-speed field-programmable gate arrays (FPGAs) can be configured to provide a low-cost interface between the digital recorder and the analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) to capture and playback the analog signals. Our design focuses on achieving the maximum possible bandwidth for each analog signal while ensuring that IRIG-A or IRIG-B timecode are recorded simultaneously (so the analog signals can be later synchronized with their digital counterparts). We have found that such a solution permits multiple analog signals from 400 KHz up to 3 MHz to be easily and inexpensively recorded on the current generation of digital recorders. Our conclusions show that such a device can permit most telemetry sites to transition completely to more reliable, cheaper, and easier-to-maintain digital recorders.en
dc.subjectRecordersen
dc.subjectDigital Recordersen
dc.subjectMultiplexorsen
dc.subjectA/D Conversionen
dc.subjectD/A Conversionen
dc.subjectPCMen
dc.subjectPAMen
dc.subjectFM-FMen
dc.description.sponsorshipInternational Foundation for Telemeteringen
dc.identifier.issn0884-5123en
dc.identifier.issn0074-9079en
dc.identifier.urihttp://hdl.handle.net/10150/608382en
dc.identifier.journalInternational Telemetering Conference Proceedingsen
dc.typetexten
dc.typeProceedingsen
dc.relation.urlhttp://www.telemetry.org/en
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