Remote Operation

Getting Started

Remote command buffering

The OSA accepts serial data via HP-IB, testing each byte. Once a complete command is received and interpreted, the HP-IB handshake is held until the command operation is completed. Once completed, the next command byte is read by the analyzer. If several commands are included in a single output statement, the computer will not be able to complete the controller output operation until the OSA has executed all of the commands. This process can hold the HP-IB interface, or program control, past a timeout cycle.

For this reason, send individual commands rather than combining them. After the command is correctly interpreted, the bus is held until the command execution is complete. If there are no other commands pending, the interface bus is released and the controller can perform other tasks while the OSA is completing the operation.

Command buffering provides an automatic synchronization between the program sending the commands and the analyzer operation. Each command will be executed before another command is recognized. There is no danger of reading or interpreting trace data in an indeterminate state, such as before a sweep has completed.

Controlling the sweep

Placing the optical spectrum analyzer in remote mode and sending the DISP:WIND:TRAC:ALL:SCAL:AUTO command finds the largest signal and optimizes the analyzer settings. This command also sets single sweep mode on the analyzer. If the DISP:WIND:TRAC:ALL:SCAL:AUTO command is not used, single sweep can be set using the INIT:CONT OFF command. The trace data present in the analyzer must be updated by taking a sweep when appropriate using the INIT:IMM command. Use this command to update the sweep after changing settings.

This mode of operation allows the program to control the sweep and ensure that data read from, or operated on in the analyzer, is updated correctly. Controlling the sweep also minimizes the amount of time the analyzer spends sweeping. At high sensitivity and high resolution settings, sweeps can take a significant amount of time. Controlling the sweep ensures that the amount of time spent acquiring data is optimized and that the data being displayed is valid for the current settings.

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