Alignment consists of eliminating a systematic shift observed with a given sensor, around a given operating point. This is used to compensate for an error linked to the process. For this reason, module replacement does not require a new alignment, though sensor replacement or a change in this sensor’s operating point do require a new alignment.
Let us suppose that a pressure sensor linked to a conditioner (1mV/mB) shows 3200 mB, when the actual pressure is 3210 mB.
The value measured by the module on a standardized scale will be 3200 (3.20 V). You can align your measurement to the value 3210 (required value).
After this alignment procedure, the measurement channel will apply a systematic offset of +10. The alignment value to enter is 3210.
The alignment value can be modified from the Control Expert screen, even if the program is in RUN.
For each input channel, the user can:
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Display and modify the required measurement value,
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Save the alignment value,
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See whether the channel already has an alignment.
The alignment offset can also be modified for each program.
The alignment is performed for each channel operating normally, with no influence on the operating modes of the module channel. The maximum variation between the measured value and the required value (aligned value) must not exceed 1000.
The alignment offset is stored in the word %MW\2.e\0.m.c.8.
