Semight-SUPPORT-FAQ-Semight Instruments

Q&A

Common Problem

Product category

？Q

Why does the ER test result of the sampling oscilloscope have a large deviation and is unstable (especially for a large Er of 1.25g or 2.5G, more than 10)?

A

Possible causes and solutions:
a. When the DCA was just started, the test was started when there was no thermal balance. The device was affected by the temperature rise, and level1 and level0 changed violently. Please start the test 15-20 minutes after the machine is started and the machine reaches the thermal balance;
b. Before the test, please calibrate dark to get a more stable Er value;
c. If the ER is still different after the above operations are completed, perform ercf compensation and align the ER test results of the calibration oscilloscope;
？Q

Why is the eye chart of the sampling oscilloscope so poor that it is easy to be dazzled?

A

a. Check the optical power, and the best use range is - 3 ~ - 6dbm
b. Eliminate that the trigger jitter is too large, cross verify and replace a bit error detector
？Q

Why is there a big difference between the optical power read by the sampling oscilloscope DCA and the actual optical power?

A

a. Check whether there is dirt inside the fiber inlet flange
b. Whether the smooth flange ceramic is broken
c. Whether optical power compensation is added inside the GUI
？Q

Why does the sampling oscilloscope have no eye chart?

A

a. Check incoming light -- check optical power
b. Check whether the modulation signal of the bit error meter is on
c. Check whether trigger is abnormal
In the above three steps, DCA of other brands can be used to verify the cross verification of optical path and high-frequency signal.
？Q

How to use sampling oscilloscope DCA? Description of specific operation steps.

A

a. Warm up the engine for 15 minutes before use
b. Connect the external trigger to the trig of DCA and connect the optical signal to the optical port (optical power recommendation - 3 to - 6)
c. Open the GUI to connect the device, and the first time it is connected will take a long time (it needs to read the internal information of the device)
d. Select the channel and rate. Note that dark current calibration must be performed after changing the channel or reopening the GUI
e. Add appropriate waveforms and appropriate mask template, check the test item on the left for normal test
？Q

The number of plug outs of the module aging board is exhausted (only for the case where the aging board has EEPROM and can record the number of plug outs)

A

Cause analysis
The plugging times have exceeded the maximum plugging times set in the system settings;
Solution
Replace the aging daughter board or increase the maximum number of plug outs in the system settings
？Q

The module is aging, and many aging boards have abnormal 12V voltage.

A

Cause analysis
① The power switches are not all turned on;
② 12V switching power supply output is abnormal;
③ The power connecting wire on the drive board is loose;
④ Abnormal driving board;
Solution
① Check whether all the power switches are turned on, such as the knob switch at the front of the machine, the flat button and the air switch at the rear;
② Use a multimeter to measure whether the voltage at the output terminal of the corresponding 12V switching power supply is abnormal;
③ Check and plug in the power connecting line on the drive board;
④ Replace or repair the drive plate.
？Q

The module is aging, and several aging boards are overheating as shown in the figure

A

Cause analysis
① The setting value of product temperature protection value in parameter setting is too low;
② The temperature sensor on the aging daughter board is abnormal;
③ Abnormal temperature control of temperature box;
Solution
① Set the product temperature protection value in the parameter setting to the normal value range;
② Check the temperature consistency of other temperature sensors on the aging daughter board, and check the abnormality of the temperature sensor;
③ Check the causes of abnormal temperature control of the temperature box, such as whether the electronic sealing valve is open, whether the solid-state relay is in a long-term on state due to electric shock and melting.
？Q

Multiple aging boards of to aging equipment display red error, and the current value in the data is 0

A

Cause analysis
It may be that the connecting wire behind the drive board is loose;
Solution
Check the connecting wire behind. If it is a single connection, replace it with a multiple connection. In addition, if multiple drive boards lose power, it is likely that the wire connected to the power brick is loose or poorly contacted;

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