Lightwave Communications LDX-3232 manual Status Reporting, Event and Condition Registers

C H A P T E R 3

REMOTE OPERATI ON

Status Reporting

Status Reporting

This section contains information that is relevant for understanding instrument error and statu reporting. It also contains information regarding the use of the instrument status for generating interrupts for interrupt driven programs or subroutines. Understanding the Operation Complete definition for the instrument is useful for programming synchronization. The Output Off Register section also contains iformation on setting some of the conditions that will force the laser current source output off.

The following sections describe the Event and Condition registers, Operation

Complete Flag, Output Off registers, and Error Messages.

Event and Condition Registers

In addition to the required GPIB-IEEE488 status reporting structures, the LDX-3232 High Compliance Current Source remote interface provides Event and Condition Registers for LASER operations. The Event Registers are used to report events that occur during the operation of the LDX-3232 High Compliance Current Source. Events differ from conditions in that events signal an occurrence once, and are not reset until the Event Register is queried, the status cleared by the *CLS command, or the instrument is powered off. Conditions reflect the current state of the device and therefore may change many times during operation. Querying a Condition Register does not change its contents.

Figure 3.3 shows the status reporting scheme of the LDX-3232 High Compliance Current Source. Each of the registers that may be accessed by a command or query has the appropriate command or query written above or below the register representation. For example, the LASER Condition Register may be queried via the LASer:COND? query.

The condition or event registers are logically ANDed with their respective enable registers. These bits are then logically ORed to form a summary message in the status byte for that particular register.

Operation Complete Definition

Note that Bit 0 of the Standard Event Status Register contains the status of the Operation Complete flag. Enabling this bit via the *ESE command allows the user to update bit 5 of the status byte. Then, if the SRE mask has bit 5 set, and the user issues an *OPC command, the SRQ (bus) signal will be generated upon completion of the currently processed commands. This bus signal (SRQ) may be used to initiate service request routines, that depend on the completion of all previous commands.

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