Details, datasheet, quote on part number: S1A

The S1A DIN-rail-mounting smart LVDT signal conditioner module from Alliance Sensors Group ends the difficulties that accompany AC-LVDT setup with built-in null indicators and front panel pushbuttons to set zero and full scale output. Engineered to work with the widest range of AC-LVDTs and inductive half-bridge LVRTs, the S1A module offers a choice of four excitation frequencies and eight analog outputs, operates LVDT sensors with over a 40 dB dynamic range of AC output, indicates most common system failures, and incorporates a 2-wire RS-485 digital communications port along with color-coded plug-in screw terminal connectors and a two-year warranty.

CompanyAlliance Semiconductor
DatasheetDownload S1A datasheet
Cross ref.Similar parts: HS1A, GS1A, 1N6478, DL4001, 1SR154050, 1SR15450, FM4001, FM4001W, S1A-E3/61T
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Features, Applications
Signal Conditioner for AC LVDTs, RVDTs, LVRTs, and Half-bridges Set-up and Operating Instructions
Alliance Sensors Group 102 Commerce Drive, Suite 8 Moorestown, NJ 08057 USA

Alliance Sensors Group, a Div. of H.G. Schaevitz LLC, 102 Commerce Drive, Unit 8, Moorestown, NJ 08057 USA, Model S1A LVDT Signal Conditioner, Measurement, Control Equipment, and Laboratory Use,

hereby declares that the product, of the following category and type: is in conformity with the provisions of the following EC/EU directives: Testing was done to requirements as stated in harmonized standards

using the methods noted hereafter: IEC 61000-4-2: 2001, IEC 61000-4-3: 2002, IEC 61000-4-4: 2004, IEC 61000-4-5: 2001, IEC 61000-4-6: 2003, and CISPR 2003. A TCF for the product is maintained for inspection at the location noted.

Alliance Sensors Group warrants the Model S1A LVDT Signal Conditioner to be free from defects in workmanship and materials for a period of two (2) years from the date of shipment. In the event a valid claim is made under this warranty, the only obligation of Alliance Sensors Group is to repair or replace the unit. Under no circumstances will Alliance Sensors Group be liable for fitness of purpose by the user or any damages, direct, consequential, or otherwise, or for any damage to any sensor connected to the S1A LVDT Signal Conditioner, or for any damage to any electronic equipment connected to the inputs or outputs of the S1A LVDT Signal Conditioner. To submit a claim under the provisions of this warranty, the claimant must secure an RMA (Returned Material Authorization) number by contacting Alliance Sensors Group at: or by sending a letter, or by e-mailing The defective unit must be returned freight prepaid to Alliance Sensors Group for inspection, accompanied by the RMA number and a letter of explanation of the purported defect. If the inspection and evaluation validates the warranty claim, the repaired or a replacement unit will be promptly returned to the claimant freight prepaid. If inspection and evaluation of the device determines that it has been misused, abused, misapplied, or modified by the user; has been subjected to a fire, flood, or mishandling; or is damaged due to improper packing for the return shipment, no warranty claim will be allowed or accepted. Instead, the unit will be returned to the claimant freight collect, along with an invoice for the evaluation charge. Any questions about Alliance's warranty provisions can be answered by contacting Alliance Sensors Group at: or by sending an e-mail query to:

In this manual, you will find a chart on page 4 for quickly connecting your AC-LVDT, AC-RVDT, LVRT, or inductive half-bridge sensor to this model S1A DIN-rail mounting, 24 Volt DC-operated signal conditioning module, and a Quick Start Guide on page 5 for calibrating it with the two front-panel push buttons, which eliminate any need for external pot adjustments. The internal DSP (Digital Signal Processor) will lead you through the various calibration steps by means of the three green LEDs on the module's front panel, as illustrated on page 2. The term LVDT is used generically throughout these instructions for any low voltage audio frequency AC-operated position sensors, i.e. LVDTs, RVDTs, LVRTs, and inductive half-bridges. You will also find the S1A specifications and a more detailed description of the advanced functions available for applications where you may wish to go beyond the basic features. Such possibilities include the master/slave synchronization of the excitation for multiple LVDTs, the open-collector failure warning switch output, the DC voltage null position indicator signal, and digital communications via the RS-485 addressable multi-drop port. The S1A LVDT Signal Conditioner is compliant for both EMI and RoHS. To assure long, maintenance-free life, all inputs and outputs are equipped with ESD protection, as well as protections against reverse voltage, overvoltage, and short circuits. Operating current and power-on inrush current are also limited by solid-state resettable fuses.

Identification of Front Panel LEDs and Switch Functions Identification of DIP Switches and I/O connections LVDT Wiring Configurations Quick Start Guide Functional Description DC Power Input` LVDT Primary Excitation AC Half-Bridge Connections Master/Slave Synchronization LVDT Output Signal DC Output Filtering Failure and Fault Indicators RS-485 Communications Expanded Calibration Procedure Terminology and Definitions Calibration Procedure Null Point Location Null Indicator Output Setting Full Scale Output Point Setting Zero Output Point Alternative Calibration Procedure Live Zero and Extra-range Outputs Using the Voltage and Current Outputs Failure Diagnostics and Reset Failure Warning Output Signals Troubleshooting LVDT Connections Grounding and Shielding Commands for the RS-485 Port End point Recalibration Hot Swapping Modules Specifications and Module Dimensions Appendix A: Error Codes and Fault Matrix


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