Vigilantplant TDLS8000, User Manual

Page: 221 / 320

<10. Troubleshooting>
10-4
IM 11Y01D01-01EN
No. Displayed name
(HART)
Description Corrective action
22 AI-2 (Temp) Low The AI-2 (temperature) input
current is less than 4 mA.
Check the process gas temperature. Check
whether the gas thermometer signal is correct.
Check whether the AI range setting is correct. For
details, see “6.3 Analog Input Settings”.
23 AI-2 (Temp) High The AI-2 (temperature) input
current is more than 20 mA.
Check the process gas temperature. Check
whether the gas thermometer signal is correct.
Check whether the AI range setting is correct. For
details, see “6.3 Analog Input Settings”.
24 External Alarm An alarm triggered by digital input
occurred.
Check the external alarm status.
25 Clock Adj
Required
The real-time clock is not
synchronized.
Set the current time.
26 Setting File Error Restored from backup due to a
setup file corruption.
Configure the settings again, and restart.
27 Calib File Error Restored from backup due to a
calibration file corruption.
Calibrate again, and restart.
49 Detect Signal
High
The detector signal level is too
high.
Contact your Yokogawa service representative.
52 Absorption High The absorption signal level is too
high.
Contact your Yokogawa service representative.
56 Outlier Reject
Lmt
The detector signal level is
abnormal.
Contact your Yokogawa service representative.
*1: For validation alarms, you can manually clear the alarm without re-executing validation.
Menu path:
[HART] “Diagnosis/Service>>Validation>>Clear val alarms”
[YH8000] “ >>Execution>>Validation>>Clear Validation Alarm”
*2: For calibration alarms, you can manually clear the alarm without re-executing calibration.
Menu path:
[HART] “Diagnosis/Service>>Calibration>>Clear cal alarms”
[YH8000] “ >>Execution>>Calibration>>Clear Calibration Alarm”
10.3 Handling Degraded Laser Transmission
For the TDLS8000 to operate normally, the optimal level of laser beam needs to reach the sensor
control unit (SCU).
The following phenomena can cause the laser beam level to degrade. These factors may occur
separately or together.
● Optical axis error: Degradation of received light level due to optical axis misalignment
• The laser beam is not directed at the detector window.
• The SCU has not be aligned with the laser incident beam.
• Misaligned flange or nozzle is blocking the laser beam.
● Clogging: The opening where the laser beam travels through is blocked or is unclean.
• Dust has accumulated inside nozzles or pipes, blocking the laser beam.
• Stain or foreign substances adhering to the process window are attenuating the laser beam
level.
● Particles: Dust in the process gas is attenuating the laser beam level.
• Smoke concentration, opacity, or particle concentration is extremely high, and not enough
laser beam is reaching the SCU.
● Laser degradation: The output power of the laser element itself has degraded.
• The laser light source has degraded or malfunctioned, and not enough laser beam is being
emitted.
3rd Edition: Jun. 10, 2016-00