A/D Conversion Method - Mitsubishi Electric MELSEC iQ-R User Manual

1.5

A/D Conversion Method

Common
An A/D conversion method can be set for each channel. The following lists available conversion methods.
• Sampling processing
• Averaging processing (time average, count average, moving average)
• Primary delay filter
• Digital filter (low pass filter, high pass filter, band pass filter)
Overview of A/D conversion
The A/D conversion can be executed as follows depending on the mode.
• In the normal mode, the A/D conversion is executed per channel. For example, when the A/D conversion is enabled for
CH1, CH2, and CH3, the A/D conversion of CH2 is executed after the A/D conversion of CH1 is completed. The A/D
conversion of CH3 is executed after the A/D conversion of CH2 is completed.
• In the simultaneous conversion mode or inter-module synchronization mode, the A/D conversion is executed
simultaneously in all channels.
■Sampling cycle
Sampling cycle is the internal A/D conversion cycle. In the normal mode, this cycle varies depending on the setting of the
number of conversion enabled channels. ( Page 22 A/D Conversion Enable/Disable Setting Function)
The following table lists the sampling cycles for the modes.
Mode
Normal mode
Simultaneous conversion mode
Inter-module synchronization mode
■Conversion cycle
Digital output values are updated on the conversion cycle of sampling processing, averaging processing, primary delay filter,
or digital filter. The following table lists the conversion cycles in each A/D conversion method.
A/D conversion method Conversion cycle
Sampling processing Sampling cycle
*2
((The time set for Time average/Count average/Moving average/Primary delay filter constant setting)  Sampling cycle)
Time average
Sampling cycle
*2
(The count set for Time average/Count average/Moving average/Primary delay filter constant setting)  Sampling cycle
Count average
Moving average Sampling cycle
*2
Primary delay filter Sampling cycle
*2
Low pass filter Sampling cycle
*2
High pass filter Sampling cycle
*2
Band pass filter Sampling cycle
*1 Values after the decimal point are omitted.
*2 These methods cannot be used in the normal mode (high speed: 1s/CH), simultaneous conversion mode, or inter-module
synchronization mode.
Normal mode (high speed: 1s/CH)
Normal mode (medium speed: 10s/CH)
Normal mode (low speed: 20s/CH)
Oversampling disable
Oversampling enable
Sampling cycle
1s  Number of A/D conversion enabled channels
10s  Number of A/D conversion enabled channels
20s  Number of A/D conversion enabled channels
5s
Inter-module synchronization cycle
5s
1 FUNCTIONS
1.5 A/D Conversion Method
1
*1
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