Yokogawa PC-Based MX100 - Manual (Page 69)

2-24 IM MX100-01E
2.7 Measures against Noise on the MX100
Technical Information described below on measures against noise is available
as reference material. For information on obtaining a copy, contact your nearest
YOKOGAWA dealer.
• Noise Interference on Recorder (TI 4D5B1-80E)
Describes the fundamentals concerning noise and its countermeasures in two parts:
basic edition and application edition.
• MX100 Performance Specifications (TI 04M08B01-00E)
Describes in detail the functions related to noise rejection specific to the MX100.
This section briefly describes the integrating A/D converter and the first-order lag filter
that the MX100 employs as measures against noise.
Integrating A/D Converter
MX100 input modules employ an integrating A/D converter for converting the measured
analog signals into digital signals. The integrating A/D converter integrates the measured
values at the specified time width. If the specified time width matches the period of the
signal you wish to reject, the signal is rejected.
Cancelled out
Integration time
DC voltage (average value)
Input voltage
(instantaneous value)
For example, if the integration time is 20 ms, signals having frequencies of 50 Hz and
integer multiples of 50 Hz can be rejected. Likewise, if the integration time is 16.67 ms,
signals having frequencies of 60 Hz and integer multiples of 60 Hz can be rejected. If
the integration time is 100 ms, signals having 10 Hz and integer multiples of 10 Hz can
be rejected. The commercial power supply is one of the noise sources. By setting these
integration times, commercial power noise of 50 Hz or 60 Hz can be eliminated.