Tektronix OA 5000 Queues, Event Handling Sequence

Status and Events

OA 5000 Series User Manual 3 --- 3 9

The OA 5000 status and event reporting systemcontains two queues: the

Output Queue and the Event Queue.

The Output Queue

The Output Queue stores up to8000 bytes of a query response while it is

waiting to be output. The Output Queueis emptied each time a new com-

mand or query message is received, so that any query response must be

read before the next command or queryis sent, or responses to earlier

queries will be lost,and an error may result.

The Event Queue

The Event Queue stores detailedinformation on up to 32 events. If more

than 32 events stack up in the Event Queue, the 32nd event is replaced by

event code 350, “Toomany events.”

Read the Event Queue with either the EVENT? query (which returns onlythe

event number) or with the EVMSG? query (which returns the event number

and a text description ofthe event). Reading an event removes it fromthe

queue.

Before reading an event from the Event Queue, youmust use the *ESR?

query to read the summary ofthat event from the SESR. This makes the

events summarized by the *ESR? read availableto the EVENT? and

EVMSG? queries, and empties the SESR.

Reading the SESR erases any events that were summarized by a previous

*ESR? read but not read from the Event Queue. Events that followan *ESR?

read are put in the Event Queue but are not availableuntil *ESR? is used

again.

Figure 3-11, on page 3---40,shows how to use the status and event handl-

ing system. In the explanationthat follows, numbers in parentheses refer to

numbers in Figure 3-11.

When an event occurs, a signal is sent tothe D ESER (1). If that type of

event is enabled in the DESER (that is, if the bitfor that event type is set to

1), the appropriate bit in the SESR isset to one and the event is recorded in

the Event Queue (2). If the corresponding bitin the ESER is also enabled

(3), then the ESB bit in the SBR is set to one(4).

When output is sent to the OutputQueue, the MAV bit in the SBR is set to

one (5).

When a bit in the SBR is set toone and the corresponding bit in the SRER is

enabled (6), the MSS bit in the SBR is set to one and a servicerequest is

generated (7).

QueuesEvent HandlingSequence

Contents

Main Page WARRANTY Page ECDeclarationofConformity Page Welcome Page Contents A Quick Tour User Reference Programming Appendices Page List of Figures List of Tables Safety Symbols and Terms Specific Precautions Page Page Page Page Installation CAUTION Removing the OA 5000 A Quick Tour Preset the OA 5000 Storing and Recalling Settings Setting a Reference Value Settings at Power Up Page Page Operator Overview The User Reference Section Operator Overview 2 --- 2 Figure 2-1: OA 5002 Front Panel User Reference Enabling/Disabling Attenuation WARNING Page Setting Attenuation Levels Specifying the Wavele ngth Setting the Attenuation Level Page Page Setting the GPIB Address Page Setting the Reference Level Measuring Insertion Loss Approximating Signal Power Page Storing and Recalling Attenuation Levels Page Page Page Setting Up the Instrument Controllers Using the GPIB Interface GPIB Requirements Setting the GPIB Address Page Command Syntax Clearing the OA 5000 ATT:DB 10 Command and Query Structure Commands Queries Headers in QueryResponses Command Entry Abbreviating Commands Concatenating Commands Message Terminators Argument Types Block Arguments Numeric Arguments Syntax Diagrams Page Commands Common Commands and Queries Device Commands and Queries ADJusting? (Query Only) ALLev? (Query Only) Page BLRN *CAL? (Query Only) *CLS (No Query Form) DESE DISable DISPlay *ESE *ESR? (Query Only) EVEnt? (Query Only) EVMSG? (Query Only) EVQty? (Query Only) FACTORY (No Query Form) HEADer *IDN? (Query Only) *LRN?orSET? *OPC *PSC RECall (No Query Form) REFerence *RST (No Query Form) *SRE *STB? (Query Only) STORe (Store Attenuation) *TST? (Query Only) VERBOSE *WAI (No Query Form) WAVelength Status and Events Registers Status Registers The Standard Event Status Register (SESR) The Status Byte Register (SBR) Enable Registers The Device Event Status Enable Register (DESER) The Event Status Enable Register (ESER) The Service Request Enable Register (SRER) The Enable Registers and the *PSC Command The Output Queue The Event Queue Queues Event Handling Sequence Status and Events Conflicts 3 --- 4 0 Programming Messages Page Page Page Page Page Appendix A: Accessories Standard Accessories Optional Accessories Page Appendix B: Specifications Page Page Page Appendix C: Interface Specifications Interface Messages Page GPIB Function Subsets Page Appendix D: Using the *OPC Query/Command Page Appendix E: Packing for Shipment Page Appendix F: Maintenance Cleaning the Optical Ports Page Changing the Optical Port Connectors Page Page Page Appendix G: Product Verification Equipment List Power Up Display Modes GPIB Address Setting Attenuation Range Shutter Attenuation and the DISABLE button 1310 nm: Page 1550 nm: 850 nm (except OA 5002): Page Appendix H: Replaceable Parts Item Names Parts Ordering Information Using the Replaceable Parts List Indentation System Abbreviations Page AppendixH: Replaceable Parts A --- 3 4 Appendices CROSS INDEX --- MFR. CODE NUMBER TO MANUFACTURER AppendixH: Replaceable Parts OA 5000 Series User Manual A --- 3 5 Page Page Page Index A B C D E F G H N O P Q R T U V W