ILX Lightwave LDC-3926339 User Manual page 75

C O M M A N D R E F E R E N C E
4
C H A P T E R
GPIB Command Reference
LASER:SYNCMDI?
Parameters
Notes
Examples
LASER:SYNCMDP?
Parameters
Notes
LASER:STEP
Parameters
Notes
Examples
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LDC-3926339
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The LASER:SYNCMDI? query returns the value of the selected channel's measured monitor
photodiode current in µA.
None. The response is an <nrf value> representing current in µA.
This is a "synchronized" measurement: the measurement system is connected to the monitor
current-measure signal when this query is received. The photodiode current measurement is made,
and the result is returned as the response. After the measurement is made, the measurement
system returns to its normal function, switching between the various signals and measuring them.
The response time to this query is from 200 msec to 250 msec, but the measurement is made as
soon as the query is received. In contrast, the laser:mdi? query returns immediately, but the
measurement can be up to 600 msec old.
LASER:syncmdi?-response: 145.5, means the measured photodiode current is 145.5 µA.
The LASER:SYNCMDP? query returns the value of the selected channel's measured optical power,
in mW.
None. The response is an <nrf value> representing optical power in mW.
Optical power is derived from photodiode current. Optical power is defined as photodiode current
divided by CalPD, the photodiode responsivity.
This is a "synchronized" measurement: the measurement system is connected to the monitor cur-
rent-measure signal when this query is received. The photodiode current measurement is made,
optical power is calculated, and the result is returned as the response. After the measurement is
made, the measurement system returns to its normal function, switching between the various
signals and measuring them.
The response time to this query is from 200 msec to 250 msec, but the measurement is made as
soon as the query is received. In contrast, the laser:mdp? query returns immediately, but the mea-
LASER:syncmdp?-response: 5.5, means the calculated optical power is 5.5 mW.
The LASER:STEP command specifies the amount the laser constant current setpoint will change
when the Laser:Inc or Laser:Dec command is issued.
An <nrf value> representing the step amount in mA, in the range 0.1 to 100.0.
The step applies to the constant-current (ILBW or IHBW mode) setpoint.
LASER:STEP 10-action: sets the laser step size to 10.0 mA.
Laser:ldi 20; Laser:Step 10.0; Laser:Inc 2,50-action: sets the Laser setpoint to 20 mA, sets the step
size to 10 mA, and performs two increments, separated by 50 mSec. After the increments, the
setpoint is 40 mA.