1. A self powered sensor may be in use, or two independent power supplies may be used for the extended analog input module of CPUAnd sensors. There is no interconnection between the ground of the two power supplies. This leads to a high fluctuation of common mode voltage, which affects the analog outputEnter the value of.

2. Another reason may be that the connecting wire on the analog module input is too long or the insulation is poor.

Remedial measures:

1. Connect the terminal m of the analog module to the corresponding terminal of the sensor to compensate for these changes.

matters needing attention:

Make sure in advance that there is only one such connection between the two power supplies. If other connections already exist, when adding a

Unexpected compensation current may occur when the block is connected!

Background knowledge:

: the analog input module has no potential separation.

: common mode voltage cannot be greater than 12V.

Common mode rejection is 40dB at 60Hz.

2. Using analog input filter

In micro / win “view” systemdatamodule “tab: analoginputfilter”.

: select the analog input to be filtered.

: select number of queries and deadtime.

The “number of queries” field contains the number of queries by which the current average of several output values can be calculated.

The value is calculated from the most recent n values, where n is the value in “number of queries”.

The dead time determines the maximum allowable offset from the average.

Editor in charge: LQ

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