HP SB manual Gpib Programming Examples, SRQ Mask Register Bit

Page 35

error

request

error

available

error

•Bit 7 (self-test error) is set if a calibration error is detected after power-up or after the self-test query (TST?) is executed. At all other times it is 0.

•Bit 6 (service request) is set when the interrupt request logic of the switch detects a reason to generate a service request interrupt on the GPIB interface.

•Bit 5 (syntax error) is set when the parser detects a syntax error in a command mnemonic.

•Bit 4 (message available) is set when a message is available in the output buffer.

•Bit 2 (settled) is set when bit 2 in the condition register changes from 0 to 1.

•Bit 0 (parameter error) is set when a parameter value is out of the range of the SB switch.

The status register can be read with the status register query (STB?) or by serial polling the GPIB interface. During power-up, the status register contains 0 and can only be read by serial polling. After initial power-up, only the settled bit (bit 2) is set to 1. The clear status byte command (CSB) and the clear device command (CLR) clear the status register. STB? also clears the status register, but only if the service request bit (bit 6) is set to 1.

SRQ Mask Register

The SRQ mask register unmasks specific events in the status register that generate service request interrupt on the GPIB interface (Table 11). The SRQ mask command (SRE) writes to the SRQ mask register. When a bit in the SRQ mask register is set to 1, the interrupt logic of the switch monitors the corresponding event bit in the status register. When a bit changes from 0 to 1, a service request interrupt is generated and bit 6 in the status register is set.

Table 11: SRQ Mask Register

SRQ Mask Register

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

 

 

 

 

 

 

 

 

self-test

n/a

syntax

message

n/a

settled

n/a

parameter

error

 

error

available

 

 

 

error

 

 

 

 

 

 

 

 

The SRQ mask register can unmask more than one event at a time. The first unmasked event to change from 0 to 1 causes an interrupt. To acknowledge this interrupt, the GPIB interface can be serial polled or the status register can be read with STB?. The first time the SB switch is serial polled after an SRQ is generated, bit 6 is on. Subsequent serial polling returns a value with bit 6 off. Similarly, STB? returns the status register with the SRQ bit set, but then the switch logic automatically clears the register. As a result, subsequent STB? queries return 0.

The SRQ mask register is cleared by powering up the SB switch, by the clear device command (CLR), or by the universal device clear command ( DC1).

GPIB Programming Examples

This section provides programming samples for controlling the SB switch over the GPIB interface. The samples were written in MS-DOS Qbasic and run on a personal computer

Programming Guide – 30

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Contents User’s Manual SB Series Fiberoptic SwitchPage Contents Programming Guide SD000153 Rev. J May Safety Information Safety Information, Instructions, and SymbolsOperating the Unit Safety InstructionsBefore Initializing and Operating the Unit Safety Proceeding Safety SymbolsSymbol CE Compliance ComplianceGeneral Information General Information and SpecificationsSingle-Common SB-C Switch Configuration Single Step Dual Common SB-E Switch Configuration Dual-Common SB-D Switch ConfigurationOptional Accessories Dual-Common Blocking SB-F Switch ConfigurationKey Features Standard AccessoriesParameter Typical Maximum SpecificationsEnvironmental ElectricalPhysical Operating Environment Getting StartedBefore Initializing and Operating the Unit Initial InspectionStoring and Shipping Cleaning Connectors Connector Cleaning connector type can vary Installing the SwitchKey Description Operating and Maintenance InstructionsFront Panel Operating KeysRear Panel External Switch Module ConnectionsExternal Switch Module without TTL Input Controls Sample Driver Application Electrical Equivalent of Driver External Switch Module with TTL Input ControlsUsing and Selecting a Channel Powering Up the SwitchControlling the Drivers Setting the Gpib AddressSetting the Interface Command Set for SC and SX Switches Controlling the Switch Remotely by RS232 Interface Controlling the Switch LocallyControlling the Switch Remotely by Gpib Interface Print #1, CLOSE? Input #1,A$ Print A$ END Calibrating the SwitchMaintaining the Switch Operating and Maintenance Instructions Gpib Pin Assignment Programming GuideMnemonic Function RS232 Interface SpecificationsGpib Interface Functions RS232 Pin AssignmentRS232 Driver Pin Assignment Operation and Query CommandsName Symbol Pin Number Signal Direction Command Parser RulesXDR i k Driver Control Operation CommandsReset Close Set Optical ChannelQuery Commands Learn Error NumberLast Number Error DriversStatus Register Status Reporting and Service Request ControlCondition Register SRQ Mask Register Bit Gpib Programming ExamplesSRQ Mask Register Serial Polling the Status Register Sending CommandsLearn Query LRN? Generating a Service Request InterruptRS232 Programming Examples Reading the Status Register Setting the Interface Command SetQuerying Status Bit Message SC Series Switch Command Set SCXXX-0XXX ModelsSX Series Switch Command Set Syntax FunctionRQS Busy Normal BAD Data Unit Failure
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