Adjust the reference offset automatically with the panel operator using the following steps.
Note: The automatic adjustment of reference offset (Fn009) cannot be used when a position loop has been formed with a host controller. Use the manual adjustment of reference offset described in (2) Manual Adjustment of Reference Off-set (Fn00A).
The servomotor power must be OFF when automatically adjusting the reference offset.
Step Display after
Operation Keys Operation
1 − −
Turn OFF the servo ON signal (/S-ON), and input the 0-V reference voltage from the host controller or external cir-cuit.
2 Press the MODE/SET Key to select the utility function.
3 Press the UP or the DOWN Key to select Fn009.
4 Press the DATA/SHIFT Key for approximately one second.
"rEF_o" is displayed.
5 Press the MODE/SET Key.
After "donE" flashes for approximately one second,
"rEF_o" is displayed again.
6 Press the DATA/SHIFT Key for approximately one second.
"Fn009" is displayed again.
Servomotor
Slight rotation (Servo ON) SERVOPACK
Servo OFF 0-V speed reference Host
controller
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
5.3 Speed Control
5
Operation
(2) Manual Adjustment of Reference Offset (Fn00A)
This method adjusts the offset inputting the amount of reference offset directly.
Use the manual adjustment of the reference offset (Fn00A) in the following cases:
• To adjust the position error to zero when a position loop is formed with the host controller and the servomo-tor is stopped by servolock.
• To deliberately set the offset amount to some value.
• To check the offset amount set in the automatic adjustment mode of reference offset.
<NOTE>
The adjusted value is not initialized by executing the Fn005 function (Initializing Parameter Settings).
Preparation
The following conditions must be met to adjust the offsets of speed reference manually.
• The write prohibited setting (Fn010) must be set to Write permitted (P.0000).
• The main circuit power supply must be ON. (Refer to 5.10.4.)
Operating Procedure
Adjust the reference offset manually with the panel operator using the following steps.
Step Display after
Operation Keys Operation
1 Press the MODE/SET Key to select the utility function.
2 Press the UP or the DOWN Key to select Fn00A.
3
Press the DATA/SHIFT Key for approximately one second.
The display shown on the left appears.
Note: When "no_oP" flashes for approximately one second, the write prohibited setting has been set in Fn010.
Change the setting in Fn010 and press the key again to enable writing. (Refer to 7.12.)
4 − Turn ON the servo ON signal (/S-ON) from an external
device. The display shown on the left appears.
5 Press the DATA/SHIFT Key for approximately one second.
The present offset amount is displayed.
6
(Example)
Press the UP or the DOWN Key to stop the motor. The dis-played value is the amount of the offset after adjustment.
7 Press the MODE/SET Key. After "donE" flashes for
approximately one second, the display shown on the left appears.
8 Press the DATA/SHIFT Key for approximately one second.
"Fn00A" is displayed again.
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
5 Operation 5.3.3 Soft Start
5.3.3 Soft Start
The soft start is a function to convert stepped speed reference input into constant acceleration and decelera-tion. The time can be set for acceleration and deceleradecelera-tion.
Use this function to smooth speed control (including selection of internal set speeds).
Note: Set both parameters Pn305 and Pn306 to "0" (factory setting) for normal speed control.
Pn305: The time interval from the time the servomotor starts until the motor maximum speed is reached.
Pn306: The time interval from the time the servomotor is operating at the motor maximum speed until it stops.
Actual accel/decel time can be calculated with the following equation.
5.3.4 Speed Reference Filter
This smooths the speed reference by applying a first order lag filter to the analog speed reference (V-REF) input.
Note: The user need not usually change the setting. A setting value that is too large, however, will slow down response.
Check the response characteristics when setting this parameter.
Pn305
Soft Start Acceleration Time
Classification Setting Range Setting Unit Factory Setting When Enabled
0 to 10000 1 ms 0 Immediately Setup
Pn306
Soft Start Deceleration Time
Classification Setting Range Setting Unit Factory Setting When Enabled
0 to 10000 1 ms 0 Immediately Setup
Speed reference
Motor speed
Speed
Speed
Pn305 Pn306
Actual accel time = Target speed Soft start time (accel time Pn305) Max. speed
Target speed Max. speed
×
Actual decel time = × Soft start time (decel time Pn306)
Max. speed
Target speed
Actual decel time Actual
accel time
Pn307
Speed Reference Filter Time Constant
Classification Setting Range Setting Unit Factory Setting When Enabled
Speed Position Torque
5.3 Speed Control
5
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 speed set in the zero clamp level (Pn501) while the zero clamp signal (/P-CON or /ZCLAMP) is ON. The SERVOPACK internally forms a position loop, ignoring the speed reference.
The zero clamp function is used for systems in which the host controller does not form a position loop for the speed reference input.
The servomotor is clamped within one pulse of the position 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.
Adjust the position loop gain (Pn102) if the servomotor oscillates in the zero clamp state. If the gain switching function is used, adjusting the 2nd position loop gain (Pn106) is required as well. For details, refer to 6.8.1 Switching Gain Settings.
(1) Factory-set Input Signal Allocations (Pn50A.0 = 0)
When Pn000.1 is set to A, the control method becomes "speed control <=> speed control with zero clamp function" and the /P-CON signal is used as a zero clamp signal.
Host controller Speed reference
Stops precisely!
V-REF
/P-CON Zero clamp (/ZCLAMP)
V-REF speed reference Speed
/P-CON (/ZCLAMP) input signal
Zero clamp function
Time
ON
ON
OFF ON OFF
OFF Set value for zero
clamp level (Pn501)
Type Connector
Pin Number Setting Meaning
Input /P-CON CN1-41 [Factory setting]
ON (closed)
The zero clamp function will be turned ON if the input volt-age of the speed reference (V-REF) drops below the set speed in the zero clamp level (Pn501).
OFF
(open) Turns OFF the zero clamp function.
Parameter Control Method When Enabled Classification
Pn000 n.A Speed control <=>
speed control with zero clamp function After restart Setup
5 Operation
5.3.5 Zero Clamp Function
(2) Changing Input Signal Allocations (Pn50A.0 = 1)
Use the /ZCLAMP signal when switching to zero clamp function.
Note: Use parameter Pn50D.0 to allocate the /ZCLAMP signal for use. For details, refer to 3.3.1 Input Signal Allocations.
To use the zero clamp function, set Pn000.1 to 0, 3, 4, 5, 6, 7, 9 or A.
Note: If Pn000.1 is set to 5, 6, 7, or 9, the zero clamp function will become invalid when the control is changed to any methods other than speed control and internal set speed control.
For speed control, the zero clamp function locks the servomotor when the speed reference drops below the set speed in the zero clamp level by setting Pn50D.0 to 7 (zero clamp function is always valid). The input signals (/ZCLAMP, /P-CON) are not necessary.