Delta VFD300C43S-HS User Manual page 765

Example: When using r to write a program
M0
If we force M0 to be 1, the frequency command will be 20.00Hz; but when M0 is set as 0,
there will be a different situation.
Case 1: When the Pr.09-33 bit 0 is 0, and M0 is set as 0, the frequency command will remain
at 20.00Hz.
Case 2: When the Pr.09-33 bit 0 is 1, and M0 is set as 0, the frequency command will change
to 0.00Hz.
The reason for this is that when the Pr.09-33 bit 0 is 1 prior to PLC scanning procedures, the
frequency will first revert to 0.
When the Pr.09-33 bit 0 is 0, the frequency will not revert to 0.
Chapter 16 PLC Function ApplicationsC2000-HS
FREQ
K2000
16-123
K1000
K1000
END