Delta MS300 Series User Manual page 332

 Requirements for negative frequency (reverse running):
Pr.03-10 = 1
Bias mode = Bias serves as the center
Corresponded analog input gain < 0 (negative); this makes the input frequency negative.
 In using the analog input addition function (Pr.03-18 = 1), when the analog signal is negative
after the addition, you can set this parameter to allow or not allow the reverse running. The result
after adding depends on the "Requirements for negative frequency (reverse running)".
In the diagram below: Black line: Curve with no bias. Gray line: curve with bias
Diagram 01
Diagram 02
Chapter 12 Descriptions of Parameter SettingsMS300
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