GB/T 15946-1995 Standard digital interface for programmable measuring equipment
Some standard content:
GB/T15946—1995
This standard is based on the IEEEStd488.1:1987 "Digital interface for programmable measuring equipment" issued by the American Institute of Electrical and Electronics Engineering (IEEE) and widely adopted internationally. It is a revision of my country's national standard GBn249.1-85 (an interface system for programmable measuring instruments, Part 1) and is equivalent to IEEEStd188:1978 "Digital interface for programmable measuring equipment". It is equivalent to IEEEStd1488.1:1987 in technical content and writing format. GBn249.1-85 was formulated in 1983 and equivalently adopts the international recommended standard IEC625.1:1979 "an interface system for programmable measuring instruments, Part 1", and is compatible with IEEEStd188:1978 "Digital interface for programmable measuring equipment". Since then, foreign countries have successively announced a series of related and more complete digital interface standards for programmable measuring equipment and corresponding device data standards, among which IEEE Std 488.1: 1987 is the most basic standard: this revision is equivalent to the adoption of the widely adopted industrial standard IEEE Std 488.1: 1987, which not only enables the product design, production and use of the digital interface system of programmable measuring equipment in my country to implement advanced technical standards, but also lays a good foundation for the future equivalent or equivalent adoption of a series of other digital interface standards. In this way, it will effectively promote the technological progress of my country's measurement industry, improve product quality, accelerate the integration with international practices, and expand foreign trade. This standard revision modifies the writing format and technical content of GBn 249.7-85 based on IEEE Std 488.1: 1987. The hierarchical division of the content of this standard is consistent with that of GBn249.1-83, with only the hierarchical names and numbers being different: the chapters, articles, sub-articles, sub-sub-articles, and paragraphs (without numbers) of this standard correspond to the articles, chapters, articles, sub-articles, and sub-articles of GBn219.1-85, respectively. However, the articles in each chapter of this standard are numbered separately, while the chapters in each article of the latter are numbered consecutively. Although some articles have been supplemented and some have been modified, the overall content of this standard is still compatible with GBn249.1-85. The main changed meanings and their changed contents can be found in the explanation of the relevant historical changes in IEEE Std 488.1: 1987\Foreword\ following this "Foreword\". This standard specifies the mechanical, electrical and functional characteristics of the digital interface of programmable measuring equipment. The device message syntax structure specification supporting this standard is specified by the corresponding standard of IFFE 188.2. This standard shall be implemented on August 1, 1995. From the date of entry into force, it will replace GB n 249.1-85 at the same time. This standard is proposed by the Ministry of Electronics Industry of the People's Republic of China. This standard is under the jurisdiction of the Standardization Institute of the Ministry of Electronics Industry. The drafting unit of this standard is the University of Electronic Science and Technology. The main drafters of this standard are: Chen Changling, Yang Anlu, Xie Qihan, Zhang Shiji, Jin Wei. GB/T 15946-1995
IE EE Foreword
(This foreword is not part of ANSI/IEEE Std 488.1:1987 TEFE Digital Interface for Programmable Measuring Equipment.) The IEEE Stl 488 standard has been continuously and widely used since its first edition in 1975. The first text in 1978 was a recognition and summary of practical experience. Through practice, it was realized that in order to improve the compatibility between independently designed products, certain clauses needed to be clearly stated. No major revisions were made to the standard in 1978, and many changes were purely editorial. However, although its basic concepts are consistent with the original version, 20 clauses have been textually changed in technical meaning. In order to make up for a small defect in the control function related to "synchronous control", "Appendix A" was added in 1980. The systematic revision is 5 The result of a regular revision every year also meets the needs of related work on the syntax structure of IEEE 488 device messages. At the same time, it is also urgently needed for some IEEE editors and our IEC counterparts to work together to make the IEEE 488 standard more consistent with the equivalent IEC 625-1 standard. The ANS1/1EEEStd488.1:1987 standard is the final text of this revision period. Similarly, the text has also undergone major technical modifications, and special attention has been paid to compatibility with earlier texts of IEEE Std 488. The use of \488.1\ is to widely distinguish it from the closely related supporting standards, A.VSI/IEEEStd488.2:1987IEEF standard encoding, format, protocol and common commands. In IFFF SLd 488.1, three of the modifications to the articles are directly to meet the needs of IEEE Std 488.2. In IEEEStdl In 488.1, the following changes are made to maintain technical compatibility between independently designed products: Clauses 1.1.2, 1.4.3.2.8.1, 2.8.3.2.8.5; RL function, to make its interpretation and use more flexible. Clause 2.3.3.3, SH function, to minimize the possibility of TACS state when LACS concept is not present. Clause 2.4.2; AH function, to cancel the obsolete text explained in Appendix A. Clauses 2.5.1, 2.6.1; T and L functions: to clarify the use of master/address,
Clauses 2.5.5, 2.6.5: T and L functions; to clarify the use of TON and LON when there is no C function. Clause 2.7.5; SR function, to cancel the provision of receiving multiple RQS messages. Clause 2.10.5; [XC function to minimize the possibility of accidental information loss. Clause 2.13.5 In Table 3, the coding of remote messages is clearly noted. Clause 4 Mechanical characteristics is consistent with the current EMC and IEC625-1 text. Clause 5.7: This new clause clarifies the unfinished interface message processing method. Appendix C: Clarifies the use of the driver type E1/E2 note in 3.3. Appendix H: Description of interface parameters in the data section, and parameter description guidelines. Appendix I: Address switch symbols and interface status indicators, and usage guidelines. Appendix J: Recommended methods for reducing radiated and conducted interference of devices specified in this standard, as well as EMC performance, cables and devices. Note: (1) Direct support IEFE Std 488.2 (2) Annexes H and J enhance consistency with future IEC 625-1 text. ANSI/IEEE Std 188.1:1987, IEEE Digital Interface Standard for Programmable Measuring Equipment Applicable to systems that communicate digitally between a group of instruments and system components in a byte: serial, hit parallel manner. The interface system specified here also applies to the devices inside the test system components. These devices can communicate through the twisted busbar system at a relatively close distance. This text consists of the following seven parts. Chapter 1 includes the scope of application of the interface: basic definition and general description. Chapter 2 is about the concept and provisions of various functions of the interface system in the standard. The individual and multiple interface functions contained in a device can process messages and change states to maintain an orderly flow of information between a group of interconnected devices. Chapter 3 specifies the electrical implementation method of the interface so that information can be transmitted between a group of interconnected devices. Chapter 4 specifies the mechanical implementation method of the interface to ensure the electrical performance of the interface system. Chapter 5 is about the requirements of the test system for the design of a single device so that it can be compatible with other devices in the test system. Chapter 6 is about the understanding of the system requirements that users of the devices specified in this standard should have. The appendix provides understanding and examples.
To connect and program devices designed to this standard, the user should have knowledge of Chapters 1 and 6. If the device used is not capable of automatically encoding and transmitting messages, the user must also have knowledge of Chapter 2. It is recommended that the user also have a general understanding of the other chapters. In addition, the user must be familiar with the device characteristics of the devices used in the system, but the description of these characteristics is beyond the scope of this standard.
The purpose of this standard to specify the interface is to ensure accurate communication between two or more devices in the system, but it does not guarantee that each device can correctly interpret all possible messages. Within the scope of this standard, the interface capabilities are allowed to be selected within a wide range, which may cause operational incompatibilities between the devices in the five-link. The device designer must fully understand the characteristics of the system so that he can make the right choice of the options provided by this standard. Similarly, the system builder must fully understand the options available to the devices in the system to ensure that the correct communication technology is used. This standard does not specify the device operating characteristics necessary to ensure system compatibility. Therefore, devices designed simply following the rules and procedures of this standard cannot guarantee absolute compatibility. The proprietary materials involved in the interfaces specified in this standard are only related to those in 2.3 and 2.4 and summarized in Appendix B.
The IEEE Standards Office calls attention to the fact that the three-wire hook technology referenced in 2.3 and 2.4 of this standard is subject to U.S. patents and corresponding patents owned by Hewlett-Packard Company in foreign countries. Although these patents appear in 2.3 and 2.4 of this standard, the IEEE has not taken a position on the validity of the patents. Hewlett-Packard Company has made an assurance to the IEEE that it is willing to grant sublicenses to any person who wishes to obtain a license under reasonable and fair terms. The commitment of Hewlett-Packard Company has been recorded by the IEEE Standards Office and the details of the license may be obtained from the Hewlett-Packard Company Legal Department, 3000 Hanover Street, Palo Alto, CA 94304. This standard is based on the work of the International Electrotechnical Commission (IEC), including Technical Committee 65, Subcommittee 65C and Working Group 3 (formerly TC66/WG8), and follows the general concepts of standards proposed by the IEC. This standard is interrelated with IEC texts. The IEEE committees responsible for drafting and interpreting this standard in the United States are: Instrumentation and Measurement Society/Instrument and Computer Interface Section (which is also the advisory committee of the US representative of IECSC65/WG3; Measurement Society/Automation Instrument Technology Section. Since metric threads are widely used in EEEE488 applications, the notes on metric threads in the early text have been deleted. Therefore, it is not necessary to blacken the relevant parts to draw attention to the metric threads. However, the surface conductivity of these parts is still very important.
ANSI/IEEEStd488. Readers of 11987 should also read the accompanying ANSI/IEEEStd488-2.1987 text. They will then realize that full compatibility with the [FFE488.2 standard requires the satisfaction of all the changes mentioned earlier in this preface. [Products produced solely in accordance with the ANSI/IEEESid488.1.1987 standard do not necessarily have full functional compatibility with IEEEStd488.2:1987]
Members of the Instrument and Computer Interface Subcommittee who participated in the preparation of the standard are: Don Loughry
Bruce Chovce
Bob Cram'
Stephen Greer
Tom Leedy
Damon Harl
Jeffrey Kodosky
Willian Maciejewski*
Glen Meldrum
Dana Trout'
Don Ware'
GB/T 15946—1995
was the voting member at the time of adoption of this standard.
The following members were the voting members who agreed to submit this document to the IEEE Standards Bureau for approval: David Ahlgren
Joln Barker
Steve Barryte
Richard Day
Ron Dass
Richard Drews
Garry Gallager
Hernard Gollomp
Arnie Greenspan
Bill Gustafson
Lary Gross
Carl Hagerling
Chris Hancuck
Faisal Imdad
B. Kowaluk
Robert Kurkjianbzxz.net
Thotas Leedy
Fred Liguri
Don Lougry
When the standard was adopted during 1EFF Standards Week on June 11, 1987, the following members participated: Tonald C. Fleckensteiri
Marco W. Mgliaro
Andrew G. Salem
Jamer H. Heall
Flennis Bodson
Marshell L. Cain
James M. Da!y ||tt | Kolodny
Vice Chairman
Clerk
joseph L.Koeplinger
Fdward Lohsc
John May
Lawrence V.MeCall
Donald T. Michael.
John MeGlaughlim
Jerry Merritt
LF Moebus
Charles Osborn
Larry Ross
Eric Sacher
Milton Slade
JRWeger
D. Williamson
Jim Weitemhagen
L.John Rankine
John P, Raganati
Gary S. Robinron
Frank I.. Rose
Robert E. Rountrce
Sava I. Sherr+
William R.Tackaberry
Willian R, Wilkens
Helen M. Waod
1.1 Scope
National Standard of the People's Republic of China
Standard digital interface for programmable measuring equipment Instrumentation1 General
GB/T15946-1995
Replaces GI3n 249. 1-85
This standard is applicable to such an interface system, which is used to connect programmable and non-programmable electronic measuring devices with other necessary devices and accessories to form an instrument system. This standard applies to the interface of such an instrument system (or some parts thereof), in which: (1) the data exchanged between the interconnected devices is digital (as opposed to analog); (2) the number of devices that can be interconnected by an in-line connection bus does not exceed 15; (3) the total transmission path length of the interconnecting cable does not exceed 20m; (4) the data rate through the interface on each signal line does not exceed 1Ml/s. The basic functions of this standard can also be used in the following digital interface applications: requiring longer transmission distances, connecting more devices, requiring better anti-interference capabilities, or a combination of these situations. For these expanded applications, different electrical and mechanical provisions may be required (e.g., symmetrical circuit structures, high threshold logic, special connections or cable structures, etc.). This standard may also be used for other "units of instrument systems, such as processors, excitation sources, displays or storage and terminal equipment used in instrument systems.
This standard is generally applicable to laboratory and production test environments with slight interference and limited physical size (limited distance between system components).
This standard only covers the connection characteristics of instrument systems, and does not include the design indicators of equipment, consideration of radio interference regulations, performance requirements and safety requirements.
Note: For the last two items, please refer to IEC34B Safety Requirements for Electrical Measuring Instruments 8T.33 and International Standards [EC:359. Indication of the working performance of electronic measuring equipment 41\
In this standard, where no further distinction is needed: the term "system" refers to a serial bit parallel standard interface system, generally including a set of circuits, cables, connectors, message libraries and control programs required to achieve non-confusion data transmission between devices; the term "device" or "device" refers to the device connected to the interface system. Any programmable measuring device or other product exchanges information through the interface system and meets the definition of the interface system: A major focus of this standard is to propose an interface system that uses external means to connect a self-contained device to other devices. This standard can also be used for the connection between the internal parts of a self-contained device. 1) The sequence numbers in square brackets correspond to the reference numbers of 1. and 1. of this standard. Approved by the State Administration of Technical Supervision on December 21, 1995, and implemented on August 1996
1.2 Self-determination
The date of this standard is:
GB/T 15946-1995
(1) Define a general system for use over limited distances;(2) Specify the mechanical, electrical and functional interface requirements that must be met by devices, independent of the device, so that these devices can be connected to each other through the system and achieve unambiguous communication;(3) Specify certain terms and definitions related to the system;(4) Enable a number of independently manufactured devices to be connected to each other as a functional system;(5) Enable devices with widely varying capabilities (from the simplest to the most complex) to be connected to the system at the same time;(6) Enable direct communication between devices without requiring all messages to pass through a control unit or intermediate unit;(7) Define a system that can impose the least restrictions on the performance characteristics of devices connected to the system;(8) Define a system that allows asynchronous communication at very different data rates;(9) Define a system that can be relatively inexpensive and can connect inexpensive devices;(10) Define a system that is easy to use. 1.3 Definitions
The following definitions apply to this standard.
This clause contains only some general definitions. Detailed definitions are given in the following clauses. 1.3.1 General System Terms
Compatibility
The degree to which components can be interconnected and used without modification when designed in accordance with the provisions of this standard (e.g., mechanical compatibility, electrical compatibility, functional compatibility).
Hook Cycle
The process of passing each data bit through an interface by means of a chained sequence of status and control signals. A chain is a fixed sequence of events in which one event must occur before the next event can occur.Interfaceinterface
The common boundary between a system and another system (or some part of a system) through which information is transmitted.Interfacesystem
A set of mechanical, electrical, and functional elements that are not different from device to device in order to enable the interface to communicate between a group of devices. Cables, connectors, driver and receiver circuits, signal conductor specifications, timing and control conventions, and functional logic circuits are typical system elements.
Local controllocal control
Another way for a device to accept programming, that is, to accept programming through its local (front panel or backplane) control so that the device can perform various tasks (also called manual control).
ProgrammableProgrammable
A feature of a device, that is, it can accept data to change its internal circuit state to perform one or more specific tasks.Remote controlremote control
A way for a device to accept program control, that is, to accept program control through its electrical interface connection so that the device can perform different tasks. System (International Electrotechnical Dictionary IEV351-01-01) is a set of interconnected components organized to achieve a given function. 1.3.2 Units connected by a bus system
Programmable measuring apparatus programmable measuring apparatus A measuring device that can perform specified operations and transmit measurement results to the system when it receives commands from the system. Terminal unit lerminal unit
GB/T 15946.. 1995
A device that terminates at an interface system, with the help of which a connection between an interface system and another external interface system is realized (including code translation if necessary).
1.3.3 Signals and paths signals and paths bidirectional bus bidirectional bus bus
A bus used by any device for bidirectional transmission of messages, that is, for both input and output. bit parallel
A group of data bits that appear simultaneously on a set of signal lines, the same number of which is used to carry information. The data bits of bit parallel can act simultaneously as a group (a bus) or independently as several independent data bits. bus bus
A pattern or group of signal lines used by an interface system to which several devices are connected and over which messages are transmitted. byte
A group of simultaneous binary digits that work as a unit, usually shorter than a computer word length (often implying a group of 8 bits).
byte serial
A sequence of data bytes encoded by parallel bits used to carry information on a common bus. high state
A relatively high positive signal level used to indicate the special message content associated with one of two binary logic states. Low state low state
A relatively low positive signal level used to indicate a specific message content associated with one of two unary logic states. signal sighal
The physical manifestation of information.
Note: In this standard, this refers to a definition of what is usually called "signal" in a general sense, and hereinafter refers to digital electrical signals. Signal levelsignal level
The amplitude of a signal relative to an arbitrary reference amplitude (voltage in this standard). Signal linesignal line
A group of signal conductors in an interface system used to transmit messages between interconnected devices. Signal parametersignal parameter
A parameter of an electrical quantity, whose value or a series of values is used to transmit information. Unidirectional busunidirectional bus
A bus used by any device for the one-way transmission of messages, that is, for input only or output only. 1.4 Overview of interface system
1.4.1 Purpose of interface system
The general purpose of interface system is to provide an effective communication link to transmit messages between a group of interconnected devices. The messages (information) carried by the interface system belong to the following two categories: (1) Messages used to manage the interface system itself, hereinafter referred to as interface messages; (2) Messages used by the devices connected to each other through the interface system. The interface system only transmits these messages, but does not directly use or process them. hereinafter referred to as device messages. Note: The detailed definition of device messages is beyond the scope of this standard. 1.4.2 Basic communication capabilities
An effective communication connection requires two basic functional elements to organize and manage the flow of information exchanged between devices: (1) A device as a listener; (2) A device as a talker; CB/T 15946-1995
(3): A device as a controller. In the context of the interface system described in this summary: (1) A device with listener capabilities can be addressed by an interface message to receive device messages from other devices connected to the interface system.
(2) A device with talker capabilities can be addressed by an interface message to send device messages to other devices connected to the interface system:
(3) A device with controller capabilities can address other devices to make them listen or talk. In addition, this device can also issue interface messages to command some specified actions in other devices. "A device with only this capability neither sends nor receives device messages. Note: The use of the term "listener" in the standard strictly applies only to the management of the interface system and does not include the broader capabilities associated with the same term in data processing. Controllers will be further classified in Chapter 2 to allow for a clear distinction between the various types of control capabilities used within the interface system. In the devices connected to the interface system, the three capabilities of listener, speaker, and controller may exist separately or simultaneously, as shown in Figure 1. In addition to the basic In addition to the original listener, speaker and controller functions, the system also provides some interface messages to perform the following operations: (1) When a device (with speaker function) requires the controller to perform a certain action, it can initiate a serial query sequence by sending a service request message. Then, the controller will obtain the status bit of each device in the sequence that may respond to the query in turn to determine which device is requesting service.
(2) When requested by the controller, the parallel query function allows a device to send a status information (request service) bit at the same time as other devices. It can be done through some interfaces. 11 messages to assign a data line to a specific device to respond to parallel queries, (3) When the slave controller receives a command: the device clear and device trigger functions enable the device to be initialized or triggered. Clearing or triggering can occur simultaneously with several selected devices or all devices in the system, (4) The remote/local control function enables a device to receive control data from the bus, local data (such as panel control) or both
1.4.3 Message Channel and Bus Structure
The connection system includes a set of sixteen signal lines. Used to connect the devices to each other. The messages can be encoded on one or a group of signal lines, depending on the specific message content and its relationship to the interface system. The bus structure consists of three groups of signal lines: (1) Data bus, consisting of several signal lines; (2) Data bit transfer control bus, consisting of two signal lines; (3) Interface calculation bus, consisting of five signal lines. Figure 1 shows the basic communication channels. The group of eight signal lines carries all seven-bit interface messages and device messages: (I) Data input and output 1 (DIO1 = DATA INPUT 1) (OUTPUTI); (8) Data Input Output 8 (DIO8).
The message bytes are carried on the DIC lines in the following manner: parallel bit, serial bit form,
instead;
bidirectionally.
Note: If necessary, a message can be carried on a separate D1 signal line. ..com device A
can speak, listen and control
(e.g.: calculator)
can speak and read
(e.g.: digital voltmeter)|| tt||Can only listen
[For example: signal generator]
Device 13
Can only talk
(For example, tape reader)
CB/T15946—1995
Figure 1 Interface capability and bus structure
Data bus
(8 signal lines)
Data bit transmission control bus
(3 signal lines)
Interface management bus
(5 signal lines)
DIO 1-8
A group of three interface signal lines is used to transfer each data sample on line 130 from a speaker or a controller to one or more listeners. t
(1) Data valid (1) AV-[ATAVALID) is used to indicate the status of the information on the DIO line (whether it is available and whether it is valid).
(2) Not ready to receive data (NRFD=NOTREADYFORDATA) indicates the device's readiness to receive data.
GB/T 15946-1995
(3) Not (not) receiving data (NDAC=NOTIDATAACCEPTED) is used to indicate the device's receiving data. The three signal lines DAV, NRFD and NDAC operate in a three-wire (interlock) hook process to pass each data bit through the interface.
Five interface signal lines are used to manage the orderly flow of information through the interface: 1) Attention (ATN=ATTENTION) is used (by a controller) to specify how the data on the DIO signal lines should be interpreted and which devices must respond to the data. (2) Interface clear (IFC = INTERFACECLEAR) is used (by a controller) to put the interface system (its parts are contained in all interconnected devices) into a known static state. (3) Service request (SRQ = SERVICEREQUEST) is used (by a device) to indicate a request for attention and to interrupt the current sequence of events.
(4) Remote control mayListen and control
(e.g. calculator)
Can speak and understand
(e.g. digital voltmeter)
Can only listen
【e.g. number generator】
Device 13
Can only speak
(e.g. tape reader)
CB/T15946—1995
Figure 1 Interface capability and bus structure
Data bus
(8 signal lines)
Data bit transmission control bus
(3 signal lines)
Connection management bus
(5 signal lines)
DIO 1-8
A set of three interface signal lines is used to pass each data bit on the 130 line from a speaker or a controller to one or more listeners. t
(1) Data Validity (1) DAV-[ATAVALID) is used to indicate the status of the information on the NDAC line (whether it is available and valid).
(2) Not Ready to Receive Data (NRFD=NOTREADYFORDATA) is used to indicate the device's readiness to receive data.
GB/T 15946-1995
(3) Not (Not) Received Data (NDAC=NOTIDATAACCEPTED) is used to indicate the device's status of receiving data. The DAV, NRFD and NDAC signal lines work in the three-wire (interlock) hook process to pass each data bit through the interface.
Five interface signal lines are used to manage the orderly flow of information through the interface: 1) Attention (ATN=ATTENTION) is used (by a controller) to specify how the data on the DIO signal lines should be interpreted and which devices must respond to the data. (2) Interface Clear (IFC-INTERFACECLEAR) is used (by a controller) to put the interface system (some of which are contained in all interconnected devices) into a known static state. (3) Service Request (SRQ=SERVICEREQUEST) is used (by a device) to indicate a request for attention and to interrupt the current sequence of events.
(4) Remote control is possible.Listen and control
(e.g. calculator)
Can speak and understand
(e.g. digital voltmeter)
Can only listen
【e.g. number generator】
Device 13
Can only speak
(e.g. tape reader)
CB/T15946—1995
Figure 1 Interface capability and bus structure
Data bus
(8 signal lines)
Data bit transmission control bus
(3 signal lines)
Connection management bus
(5 signal lines)
DIO 1-8
A set of three interface signal lines is used to pass each data bit on the 130 line from a speaker or a controller to one or more listeners. t
(1) Data Validity (1) DAV-[ATAVALID) is used to indicate the status of the information on the NDAC line (whether it is available and valid).
(2) Not Ready to Receive Data (NRFD=NOTREADYFORDATA) is used to indicate the device's readiness to receive data.
GB/T 15946-1995
(3) Not (Not) Received Data (NDAC=NOTIDATAACCEPTED) is used to indicate the device's status of receiving data. The DAV, NRFD and NDAC signal lines work in the three-wire (interlock) hook process to pass each data bit through the interface.
Five interface signal lines are used to manage the orderly flow of information through the interface: 1) Attention (ATN=ATTENTION) is used (by a controller) to specify how the data on the DIO signal lines should be interpreted and which devices must respond to the data. (2) Interface Clear (IFC-INTERFACECLEAR) is used (by a controller) to put the interface system (some of which are contained in all interconnected devices) into a known static state. (3) Service Request (SRQ=SERVICEREQUEST) is used (by a device) to indicate a request for attention and to interrupt the current sequence of events.
(4) Remote control is possible.
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