Status Reporting; Event And Condition Registers; Operation Complete Definition - ILX Lightwave LDX-32420 User Manual

Status Reporting

This section contains information that is relevant for understanding instrument
error and status 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 information 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-32420 remote interface provides Event and Condition Registers for LASER
operations. The Event Registers are used to report events that occur during
instrument operation. 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 instrument 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-32420. 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.
01_10
R E M O T E O P E R A T I O N
Status Reporting
3
C H A P T E R
33
LDX-32420
