Wavelength Electronics LFI-3751, Руководство пользователя, Страница: 29 / 132

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7. Autotune Error Codes
Four error conditions can occur that will abort the Autotune sequence. When
an error occurs, the error is displayed as follows. The error is also returned in
the
[RUN / STOP] RS-232 command:
E001 – Error 1: Zero Value Current Limit Error
•
The LFI-3751 detected that either the required positive or negative
current limit was set to zero. The LFI-3751 cannot drive the
temperature toward the setpoint.
•
Correction: Set the limit to something other than zero.
E002 – Error 2: Current Limit Cannot Reach SET T
•
The LFI-3751 determined the current limit is not high enough to reach
the desired operating temperature entered in SET T.
•
Correction: Increase the current limit or review the design to see why
the desired temperature differential cannot be achieved.
E003 – Error 3: Non-uniform TE I Step Measured
•
It is critical that the step current, TE I, remain constant throughout the
Autotune parameter measurements for L, Rmax, and T . If the output
current is limited because the compliance voltage of the LFI-3751 has
been reached, the step current will not be uniform.
•
Correction: Reduce the current limit or use a thermoelectric with
a lower voltage requirement.
E004 – Error 4: Zero Slope
•
The load temperature is not changing over time. Either the sensor
signal is not changing, no current is fl owing to the thermoelectric,
or even with the maximum current fl owing to the thermoelectric the
load temperature is not changing.
•
Correction: Verify that the sensor is in good thermal contact with
the load and that it is properly wired to the LFI Output Connector.
Verify that the thermoelectric is properly wired to the LFI Output
Connector.
Chapter 2 - Front Panel Operation
Autotune PID Operation