VXI SVM2608 user manual Introduction, Overview

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SECTION 1

INTRODUCTION

INTRODUCTION

The SVM Series leverages off VXI Technology’s line of high-density modular VXIbus instruments, but are optimized for the VMEbus. All SVM instruments are designed to provide all the features of test instrumentation in other platforms such as GPIB or VXI. These features are achieved in hardware rather than in a driver. This approach to the interface design guarantees the user that all communications to the module occur in microseconds, as opposed to several milliseconds, considerably improving system throughput. The board is equipped with a microprocessor which significantly increases the module’s functionality and task performing capabilities.

The SVM2608 is a ruggedized circuit card designed for insertion into a convection-cooled VME chassis. It is a double height VME size module (6U) of single slot width and conforms to all physical requirements as specified by VME specifications. The VME interface is compatible with the VME32/64x configuration with two 160-pin (32 x 5) backplane connectors (P0 – P1). The SVM2608 consists of four low-speed (100 kSamples/s) channels and, with the addition of the -01 Option, can include two, high-speed (20 MHz) channels.

OVERVIEW

The SVM2608 is a precision, four channel digitizer capable of capturing data on all four channels simultaneously either in FIFO (or “real-time”) mode or Linear (or “burst”) mode. A processor enables the user to perform a variety of calculations with the data acquired. Each channel is also capable of measuring voltage and resistance. All four channels can measure voltage at the same time, but resistance can only be measured one channel at a time. Resistance can be measured in two different modes: 2-wire or 4-wire. Both modes use a local current source to inject a current into the resistor under test and then measure voltage across the resistor.

All four channels are independent of one another. The front end of each channel has both a variable gain amplifier and an attenuator, thus allowing for full ADC scale measurements of signals from 1 V to 100 V. Before being digitized, the signal can be passed through a Low Pass Filter (LFP) with a cut-off frequency of 20 kHz. The ADC is a 16-bit converter capable of taking as many as 100 kSamples/s on a scale of -10 V to +10 V. To compensate for offset and gain variation in the ADCs, each channel has two 12-bit DACs that are used to calibrate the offset and the gain on each channel ADC. These calibrations are performed at the factory using precision voltage reference sources.

SVM2608 Introduction

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Contents SVM2608 VXI Technology, Inc Table of Contents Self Test Command Restricted Rights Legend WarrantyLimitation of Warranty CertificationSteve Mauga, QA Manager EMCUse Proper Power Source Service should only be performed by qualified personnelTerms and Symbols Use Proper Power CordImproper Use Avoid Electric ShockGround the Product Operating ConditionsTechnical Support VXI Technology World HeadquartersVXI Technology Cleveland Instrument Division VXI Technology Lake Stevens Instrument DivisionVXI Technology, Inc SVM2608 Preface Overview IntroductionScale Triggering Acquiring DataPre-Trigger Linear ModeDelayed Trigger Test Bus Fifo ModeCommands CalibrationsOption SVM2608 Block Diagram Physical Description SVM2608 Environmental SpecificationsCH1I+ GND CH3I+ Exttrigin CH0I CH2I Front Panel Interface WiringGND CH1I CH3I GNDMtbf SVM2608 SpecificationsOption 1 SVM2608-01 VXI Technology, Inc SVM2608 Introduction Setting the Chassis Backplane Jumpers Calculating System Power and Cooling RequirementsRotary Switch Locations Setting the Base AddressMSB LSB ExampleDivide Decimal Module INSTALLATION/REMOVAL Switch to C and the front switch toRegister Offset Device Memory MapsFunction Offset ReservedMS = Most Significant LS = Least Significant SVM2608 A32 Register MAP0x72 Command Register Channel 0x74 Databyte Ordering Determining the Register Address Sysfailctl Accessing the RegistersDescription of Registers EXT Trig Slope Force Trigger, Start Register 0x02 Read & WriteINTLVL2 HSTRIGSRC2External Trigger Level 0x06 Read & Write TimeoutctlReserved ATTN-GAIN1-GAIN0 2WIREOHMS4WIREOHMS LINEAR/FIFOKHz Channels 0-3/5 MHz Channels 4-5 LPF Control This bit Sample Rate 0x0C, 0x34, 0x5C, 0x84 Read & WriteSample Rate 0x0E, 0x36, 0x5E, 0x86 Read & Write Sample Rate, High-Speed 0xAE, 0xD6 Read & Write Sample Rate, High-Speed 0xAC, 0xD4 Read & WriteTimeout 0x1C, 0x44, 0x6C, 0x94, 0xBC, 0xE4 Read & Write Reserved Registers 0xF8 0xFC Fifo Data 0x24, 0x4C, 0x74, 0x9C, 0xC4, 0xEC Read OnlyFifo Data 0x26, 0x4E, 0x76, 0x9E, 0xC6, 0xEE Read Only Trigger Delay = Measurement Commands Microprocessor CommandsCaptured Data Calculations Resistance Measurement Dynamic Method Self Test CommandResistance Measurement Offset Method Example Preset Setting Measurement CommandsTrigger Event Forced Trigger Calibration CommandsSample Points Sample RatePage Error Processing There are no errors in the queue Diagnostic Commands Changes become effective the next time the module powers up Examples Example 2 Setting Channel 2 to Acquire 200,000 SamplesExample 3 Setting Channel 2 to Pre-acquire 100,000 Samples Timeout Register = Timeout Base * 213 + Timeout Counter Timeout Counter = Timeout / Timeout Base ClockVXI Technology, Inc SVM2608 Programming Data Swapping Example Appendix aVXI Technology, Inc SVM2608 Appendix a Index
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