Lightwave Communications LDX-3232 manual Saving and Recalling Under Remote Operation

C H A P T E R 5

FUNCTIONS AND FEATURES

Saving and Recalling Under Remote Operation

To recall a previously saved instrument setup, press the SELECT switch until the RECALL indicator led becomes lit. The instrument will display a RECALL "bin" number on the display. If you desire to change the RECALL bin, press and hold the SET switch and rotate the adjust knob until the desired bin number is displayed. Releasing the SET switch completes the RECALL operation. The instrument is restarted and the front panel parameters are reconfigured to the new parameters saved under that bin number.

The factory default values for front panel parameters may be restored by recalling "bin" zero (0). See Table 2.1 for the default settings.

Saving and Recalling Under Remote Operation

For saving under remote operation, use the command *SAV x, where x is the desired "bin" number (1-10). For a recall under remote operation, use the command *RCL x, where x is the desired "bin" number (0 - 10).

Using the Laser Compliance Voltage Adjustment

For applications where you need to have critical protection of the laser, we recommend the following. Using a 1 Ω resistor or other non-critical load, set the LASER voltage limit as described in Chapter 2.

Then with the LASER output on, slowly increase the LASER current and watch the LASER voltage measurement. Press the (DISPLAY) SELECT push button to see the voltage. At about 0.25 V below the LASER voltage limit value, the VOLTAGE LIMIT warning indicator will become lit on the display. Continue to adjust the current upwards until the voltage limit is reached and the output is shut off. Record the voltage at that the LASER output shuts off. It should be within the specification of the LASER voltage limit accuracy. However, there is typically some offset error. For example, if the LASER voltage limit is set to 5.0 V, the actual voltage where it shuts off may be 4.9 V. This error term of 0.1 V should be considered when setting the LASER compliance voltage limit.

The closer the LASER voltage limit shut off point is to the operating voltage of your laser, the faster the circuit will work in the event of an open circuit. Some experimentation may be necessary for optimum results.

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