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Synchronizing controller
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MG.10.N4.02 - VLT is a registered Danfoss trademark
776
Input status (read only):
Digital control (par. 753 and par. 754): This parameter is showing the actual status of the
8 digital inputs (I1 - I8) on MK3A as a binary code.
Example:
Input 3.7 and 8 high
776 = 11000100
Input 1 and 3 high
776 = 101
Field bus control (par. 753 and par. 754): This parameter is showing the status of the field
bus control word (PCD 1) as a decimal value.
Example:
Bit 3,7 and 8 high
776 = 196
Bit 1 and 3 high
776 = 5
777
PID-sample time
The parameter is setting the sample time of the control algorithm. The value should be
increased if:
•
The pulse frequency is very low, e.g. 1 to 2 quad counts per sample time (you need
at least 10 to 20 quad counts per sample time).
•
The system is very slow and heavy (high inertia). Controlling systems with 1 ms can
make big motors vibrate.
The correct value can be calculated automatically, see test run parameter 729.
NOTE!
The parameter setting has direct influence on the PID loop; if you for example double the
Sample time the P-portion (parameter 702) also has the double effect.