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Features and Functions

24

Keysight U2781A User’s Guide

Introduction

The Keysight U2781A USB modular instrument chassis provides six USB modular 

slots and is equipped with 200 W universal AC power supply and built-in over 

current protection circuit. A 10 MHz system reference clock is supplied to each 

modules slots. There are two temperature sensors and a monitoring fan control 

circuit to monitor the internal temperature and speed of the fan. The fan is mainly 

used for heat dissipation. 
The chassis also provides external 10 MHz reference clock, external trigger in and 

trigger out functions via BNC connectors at the rear panel.
The key function for the chassis is to provide users with flexibility when using the 

U2781A modular instrument chassis. The modular chassis allocates housing for 

six USB modules with built-in power supply. The USB backplane provides a 

means to synchronize the modules. 
The key features of the U2781A USB modular instrument chassis are as follows:
– Simultaneous Synchronization (SSI)
– Star trigger
– Internal and external 10 MHz reference clock
– Trigger in and trigger out signals
– Standard SCPI commands 
– IVI-COM driver compatibility
– USBTMC 488.2 compliant
– Hi-Speed USB 2.0 interface
The key functions of the Keysight U2781A USB modular instrument chassis will be 

elaborated in the following sections.

Содержание U2781A

Страница 1: ...Keysight U2781A USB Modular Instrument Chassis User s Guide ...

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Страница 4: ... the public or 2 Relinquish to or otherwise provide the government rights in excess of these rights customarily provided to the public to use modify reproduce release perform display or disclose commercial computer software or commercial computer software documentation No additional government requirements beyond those set forth in the EULA shall apply except to the extent that those terms rights ...

Страница 5: ...Keysight U2781A User s Guide 5 Safety Symbols The following symbols indicate that precautions must be taken to maintain safe operation of the instrument Direct current Warning ...

Страница 6: ... the cables provided Observe all markings on the device before connecting to the device Turn off the device and application system power before connecting to the I O terminals When servicing the device use only specified replacement parts Do not operate the device with the removable cover removed or loosened Do not connect any cables and terminal block prior to performing self test process CAUTION...

Страница 7: ...n was proven The CSA mark is a registered trademark of the Canadian Standards Association A CSA mark with the indicators C and US means that the product is certified for both the U S and Canadian markets to the applicable American and Canadian standards The RCM mark is a registered trademark of the Australian Communications and Media Authority This ISM device complies with the Canadian ICES 001 ...

Страница 8: ...toring and Control Instrument product The affixed product label is as shown below Do not dispose in domestic household waste To return this unwanted instrument contact your nearest Keysight Service Center or visit http about keysight com en companyinfo environment takeback shtml for more information Sales and Technical Support To contact Keysight for sales and technical support refer to the suppor...

Страница 9: ...duct Overview 17 Product Outlook 17 Dimensions 18 Standard Purchase Items Checklist 19 Installations and Configurations 20 General Maintenance 21 2 Features and Functions Introduction 24 USB Backplane 25 Trigger Bus TRIG 0 7 27 External Trigger Out 28 External Trigger In Star Trigger 29 Simultaneous Synchronization SSI 30 Single Master multiple Slaves 32 Multiple Master multiple Slaves 35 System R...

Страница 10: ...10 Keysight U2781A User s Guide Identifying Modules Location 40 Geographical Address 40 Modules Identification 41 3 Characteristics and Specifications ...

Страница 11: ... Mhz Reference Clock and External Trigger In 29 Figure 2 4 Synchronization between modules in the chassis 31 Figure 2 5 Single Master multiple Slave triggering with DAQ 32 Figure 2 6 Single Master multiple Slave triggering 33 Figure 2 7 Multiple Master multiple Slave triggering 35 Figure 2 8 Block diagram of temperature monitoring and fan control 38 Figure 2 9 Identifying modules location 41 ...

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Страница 13: ...onnector 25 Table 2 2 Trigger out bits for U2300A U2500A and U2600A Series DAQ devices 28 Table 2 3 Example of configurations for single Master multiple Slaves using DAQ and U2700A Series modular products 34 Table 2 4 Example of configurations for multiple Master multiple Slaves 36 ...

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Страница 15: ...neral Maintenance 21 This chapter provides an overview of the U2781A USB modular instrument chassis the product outlook and dimension This chapter also contains instructions on how to get started with the chassis from the installation of modules to the chassis to the installations of hardware and software to the start up and configurations of Keysight Measurement Manager application software ...

Страница 16: ...2 Standards work seamlessly with Keysight Measurement Manager software and can be controlled remotely via industry standard SCPI commands In addition the U2781A modular instrument chassis comes with Keysight IO Libraries Suite 14 2 The U2781A modular instrument chassis comes with star trigger bus which offers precise synchronization between USB modules and the external trigger signal The star trig...

Страница 17: ...Getting Started 1 Keysight U2781A User s Guide 17 Product Overview Product Outlook Front View Rear View Module L Mount Kit ON OFF switch Bumper Trigger In USB Port Trigger Out Ext 10 MHz AC Input ...

Страница 18: ...1 Getting Started 18 Keysight U2781A User s Guide Dimensions 270 00 mm 271 20 mm 197 00 mm ...

Страница 19: ...USB modular instrument chassis If there are missing items contact the nearest Keysight Sales Office Power cord USB Extension Cable Keysight USB Modular Products and Systems Quick Start Guide Keysight USB Modular Products and Systems Product Reference DVD ROM Keysight Automation Ready CD ROM contains the Keysight IO Libraries Suite Functional Test Certificate ...

Страница 20: ...81A USB modular instrument chassis with the Keysight Measurement Manager follow the step by step instructions as shown in the Keysight USB Modular Products and Systems Quick Start Guide NOTE You need to install IVI COM driver before using the U2781A Series with Keysight VEE LabVIEW or Microsoft Visual Studio ...

Страница 21: ...aning steps are as follows 1 Power off the chassis device and remove the power cord and I O cable from the chassis 2 Shake out any dirt that may have accumulated inside the chassis device 3 Wipe the chassis with a dry cloth NOTE Repair or service which are not covered in this manual should only be performed by qualified personnel ...

Страница 22: ...1 Getting Started 22 Keysight U2781A User s Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Страница 23: ...rnal Trigger Out 28 External Trigger In Star Trigger 29 Simultaneous Synchronization SSI 30 Simultaneous Synchronization SSI 30 Chassis Temperature Monitoring 38 Fan Speed Monitoring 39 Identifying Modules Location 40 This chapter provides information for better understanding of the features and functions of the U2781A USB modular instrument chassis ...

Страница 24: ...igger in and trigger out functions via BNC connectors at the rear panel The key function for the chassis is to provide users with flexibility when using the U2781A modular instrument chassis The modular chassis allocates housing for six USB modules with built in power supply The USB backplane provides a means to synchronize the modules The key features of the U2781A USB modular instrument chassis ...

Страница 25: ...ND LBL3 GA2 TRIG6 GND LBR3 GND 4 GND LBL4 STAR_TRIG GND TRIG2 LBR4 GND 3 GND LBL5 GND TRIG5 GND LBR5 GND 2 GND LBL6 CLK10M GND TRIG3 LBR6 GND 1 GND LBL7 GND TRIG4 GND LBR7 GND Z A B C D E F Table 2 1 Pin information of SSI connector SSI timing signal Functionality 12V 12 V power from backplane GND Ground BRSV Reserved pin TRIG0 TRIG7 Trigger bus 0 7 STAR_TRIG Star trigger CLK10M 10MHz reference cl...

Страница 26: ...2 Features and Functions 26 Keysight U2781A User s Guide Figure 2 1 USB backplane block diagram ...

Страница 27: ... modules set the particular module as MASTER and the rest as SLAVE refer to Simultaneous Synchronization SSI for more details The control signal is sent from the MASTER module to the SLAVE modules through this trigger bus See following figure for the bus architecture Figure 2 2 Block diagram of Trigger Bus TRIG 0 7 and Trigger Out In addition the trigger bus can also be used to carry out the pre c...

Страница 28: ...ovided by U2300A U2500A and U2600A Series DAQ whereas for U2700A Series modular products user is allowed to choose any trigger line from the trigger bus TRIG 0 7 as an external trigger source The SCPI command below is used to select one of the lines or bits of the trigger bus TRIG 0 7 as an external trigger source TRIGger OUT 0 1 2 3 4 5 6 7 Table 2 2 Trigger out bits for U2300A U2500A and U2600A ...

Страница 29: ... This trigger signal is sent from external to each slot through a 1 to 6 CLK buffer The slot to slot skews are minimized to ensure that trigger signal reaches all six slots simultaneously Refer to the following figure for the star trigger bus architecture illustration To set star trigger as the module trigger source the following SCPI command is sent to the modules OUTP TRIG SOUR STRG Figure 2 3 B...

Страница 30: ...t Manager AMM SSI allows users to set the modules as MASTER or SLAVE The MASTER module sends the SSI signal to the slave modules via the backplane trigger bus TRIG 0 7 SLAVE modules will then receive the signal and begin synchronization with MASTER module There are two SSI configuration modes available single Master multiple Slaves and multiple Masters multiple Slaves NOTE Only ONE master can be a...

Страница 31: ... USB Interface To PC with AMM SLAVE module 1 SLAVE module 2 FPGA SSI Signals SSI Signals SSI Trigger Bus Chassis SLAVE module 1 SLAVE module 2 FPGA SSI Signals MASTER Module FPGA SSI Signals 55 pin Connectors 55 pin Connectors 55 pin Connectors 55 pin Connectors 55 pin Connectors 55 pin Connectors 55 pin Connectors 55 pin Connectors 55 pin Connectors ...

Страница 32: ...ght U2300A U2500A and U2600A Series DAQ only When there is one or more U2300A U2500A or U2600A Series DAQ in the SSI configuration SSI allows users to set only one of the modules as MASTER and others as SLAVE through AMM Alternatively users can also set this configuration using the SCPI commands Figure 2 5 Single Master multiple Slave triggering with DAQ NOTE Refer to U2300A U2500A and U2600A Seri...

Страница 33: ... and U2700A Series modular products With one DAQ configured as Master all of the other U2700A Series modular devices can only be configured as Slave to receive the event of the signal as shown in Table 2 2 Figure 2 6 Single Master multiple Slave triggering Table 2 3 shows some examples of supported and not supported configurations ...

Страница 34: ...aves using DAQ and U2700A Series modular products Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 DAQ U2701A U2702A U2761A U2722A DAQ Supported configurations Configuration 1 M T0 T7 S T0 S T3 S T7 S T0 T7 Configuration 2 None M T1 S T1 S T1 None Configuration 3 M T0 T7 None None None S T0 T7 Not supported configurations Configuration 1 a M T0 T7 M T1 S T1 S T2 None Configuration 2 b S T0 T7 M T1 S T1 S...

Страница 35: ...e Slaves are allowed in order to perform multiple synchronizations simultaneously This configuration is only supported by U2700A Series modular products Figure 2 7 Multiple Master multiple Slave triggering Table 2 4 shows some examples of supported and not supported configurations Example of configurations for multiple Master multiple Slaves ...

Страница 36: ... Example of configurations for multiple Master multiple Slaves Slot 1 Slot 2 Slot 3 Slot 4 Slot 5 Slot 6 U2701A U2702A U2761A U2751A U2722A Supported configurations Configuration 1 M T0 S T0 S T0 None S T0 Configuration 2 S T1 M T1 None None S T1 Configuration 3 M T0 M T1 S T0 None S T1 Configuration 4 Out M T1 S T1 In None S T1 Configuration 5 Out In In None In Not supported configurations Config...

Страница 37: ...efer to Figure 2 3 for the block diagram Every clock trace is in equal distance to ensure that the distance of the slot to the slot skew is minimized Users can use this common reference clock signal to synchronize multiple modules in a measurement or control system The default SCPI command of ACQuire RSIGnal AUTO will scan through and detect if there is any valid clock source from the external BNC...

Страница 38: ...nsors to sense the inner temperature of the chassis The temperature control circuitry communicates with backplane USB device through an I2C interface as illustrated in following figure Figure 2 8 Block diagram of temperature monitoring and fan control The SCPI command below queries the temperature reading from the sensors in degree Celsius C SYSTem TEMPerature 1 2 ...

Страница 39: ...h a fan speed control circuit It is used to monitor the fan status and speed The control circuit communicates with backplane USB device via I2C interface Refer to Figure 2 8 To query the fan status send the SCPI command below SYSTem FSTATus 1 2 To query the fan speed in revolutions per minute rpm send the SCPI command below SYSTem FSPeed 1 2 ...

Страница 40: ...t address pin which is designated as a location identity for USB modules The address for all six slots are as below The USB modules are able to read this 3 bit data and know which slot the module is plugged in To read the geographical address of each module the SCPI command below is used SYSTem CDEScription Slot Address 1 001 2 010 3 011 4 100 5 101 6 110 ...

Страница 41: ... the synchronization or triggering event begins Follow the steps below 1 Send the following command to the modular chassis to trigger it This command will be used to transmit the number to all USB modules via Trigger Bus TRIG 0 7 You can choose from 0 to 255 for your chassis number SYSTem IDentity 0 1 2 3 255 2 Send the following command to every module in the chassis to query each of the slot and...

Страница 42: ...is identification operation the trigger bus is used Hence any triggering activities on the backplane would be blocked 5 Prior to any triggering activities you must stop the configuration activity by sending the following command SYSTem IDentity 0 OFF NOTE Do not execute the above mentioned steps when the USB modules are in the process of acquiring data You do not need to perform the above pre conf...

Страница 43: ...nt Chassis User s Guide 43 3 Characteristics and Specifications For the characteristics and specifications of the U2781A USB Modular Instrument Chassis refer to the datasheet at http literature cdn keysight com litweb pdf 5989 9923EN pdf ...

Страница 44: ...3 Characteristics and Specifications 44 Keysight U2781A User s Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Страница 45: ...ion is subject to change without notice Always refer to the Keysight website for the latest revision Keysight Technologies 2006 2017 Edition 8 June 1 2017 Printed in Malaysia U2781 90003 U2781 90003 www keysight com ...

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