YASKAWA SGDV - Zero Clamp Function

5.3 Operating Using Speed Control with Analog Voltage Reference
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Operation
5.3.5 Zero Clamp Function
The zero clamp function locks the servo when the input voltage of the speed reference (V-REF) drops below
the set speed in the zero clamp level parameter (Pn501) while the zero clamp signal (/P-CON or /ZCLAMP) is
ON. The SERVOPACK internally forms a position loop, ignoring the speed reference.
The servomotor is clamped within one pulse of when the zero clamp function is turned ON, and will still
return to the zero clamp position even if it is forcibly rotated by external force.
The zero clamp function is used for systems where the host controller does not form a position loop for the
speed reference input.
<Terms>
Servo lock: A stopped state of the motor in which a position loop is formed with a position reference of 0.
Adjust the position loop gain in Pn102 if the servomotor oscillates in the zero clamp state. If the gain switch-
ing function is used, adjusting the 2nd position loop gain in Pn106 is required as well. For details, refer to
6.8.1 Switching Gain Settings.
Host controller
Speed reference
Stops precisely!
V-REF
/P-CON
Zero clamp
(/ZCLAMP)
V-REF speed reference
Speed
P-CON (/ZCLAMP)
input signal
Set value for zero
clamp level (Pn501)
Zero clamp
function
Time
ON
ON
ON
OFF OFF
OFF
Speed reference
Zero clamp
V-REF
CN1
41
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/P-CON
SERVOPACK
(/ZCLAMP)