Problem: In analog mode, there is no output signal (signal level is 0 mA).
The probe cable is not properly
connected.
Check the cable connection and correct it if needed.
Power input to the probe is off. Turn on the power input.
The analog output error level is
configured to be 0 mA, and the
probe is performing start-up
purge or is in error state.
Wait for 5 minutes for the possible start-up purge to finish. If the
output remains 0 mA after 5 minutes, check the probe
diagnostics with the Insight software (see
Problem: At start-up in analog mode, the probe remains in the error state for over 5 minutes.
Possible Cause:
Solution:
The analog output scaling is
unsuitable. For example, the
scale 0 ... 5 %RH is too narrow
compared to the full
measurement scale of RH.
Check the analog output scaling with the Insight software and
correct the scaling if needed (see
There is a probe or sensor error. Check the probe diagnostics with the Insight software (see
Vaisala Insight Software (page 28)
).
Problem: In analog mode, start-up purge is not performed.
Possible Cause:
Solution:
The probe is in digital mode at
start-up (pin #5 is floating).
Check pin #5. See
9.2 Analog Output Error State
The probe sets the analog output channel into a defined error level instead of the measured
result in three situations:
• Probe is performing start-up purge (duration 4 minutes).
• Probe detects a measurement malfunction. This means an actual measurement problem,
such as sensor damage, or unsuitable environmental conditions.
• Measured value(s) are outside the scaled output range.
The default error level for the analog outputs is 3.6 mA. You can change the error level (range
0 ... 25 mA) with the Insight software and via Modbus (registers 0706
hex
and 0806
hex
).
More Information
‣
Configuration Registers (page 48)
HPP272 User Guide
M211972EN-B
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