Pn400 = 0003.0 : Motor rated torque at 3.0 V [Factory setting]
Note: The value is 30, but it will be displayed on the operator as 0003.0.
Connect the pins for the T-REF signal and SG to the analog reference output terminal on the host controller when using a host controller, such as a programmable controller, for torque control.
Note: Always use twisted-pair cables to control noise.
Parameter Meaning When Enabled Classification
Pn000 n.2 Torque control After restart Setup
Type Signal Name Connector
Pin Number Name
Input T-REF CN1-9 Torque reference input
SG CN1-10 Signal ground for torque reference input
Speed Reference Input Rotation Direction Torque
+3 V Forward Rated torque
+1 V Forward 1/3 rated torque
–1.5 V Reverse 1/2 rated torque
SG CN1
10 T-REF 9 D/A
0 V SERVOPACK Host
controller
Approx.
14 kΩ
5.5 Torque Control
5
Operation
(2) Parameter Setting
Using Pn400, set the analog voltage level for the torque reference (T-REF) that is necessary to operate the ser-vomotor at the rated torque.
Note: A torque reference above the rated torque can be applied but it may cause an overload (high load) alarm (A.710) or overload (low load) alarm (A.720) if excessive torque is output for a long time. Refer to 10.1.2 Troubleshooting of Alarms.
5.5.2 Reference Offset Adjustment
In torque control, the servomotor may rotate at a very low speed with a voltage reference of 0 V. This occurs because the internal reference voltage of the SERVOPACK has a slight offset of a few millivolts. It is called
"offset."
If the servomotor rotates at a very low speed, the offset needs to be eliminated with the offset adjustment func-tion.
Use either automatic adjustment or manual adjustment. Automatic adjustment uses the automatic adjustment parameter for reference offset (Fn009). Manual adjustment uses the manual adjustment parameter for refer-ence offset (Fn00B).
Pn400
Torque Reference Input Gain
Classification Setting Range Setting Unit Factory Setting When Enabled
10 to 100 0.1 V/rated torque 30
(Rated torque at 3.0 V) Immediately Setup Speed Position Torque
Torque reference voltage (V) (Rated torque)
300 200 100
-300 -200 -100
1 3 10 12
0 -3 -10
-12
Setting range (1.0 to 10.0 V) Factory Setting
Output torque (%)
Input voltage range (0 to ±12 V)
Output torque Output torque
Offset
Offset adjustment
Torque reference voltage Torque
reference voltage
The offset is adjusted in the SERVOPACK.
Offset Adjustment Range: -127 to +127 (Torque Reference: -1905 to 1905 mV Offset Setting Unit: 15.0 mV)
5 Operation
5.5.2 Reference Offset Adjustment
(1) Automatic Adjustment of Reference Offset (Fn009)
The automatic adjustment of reference offset measures the amount of offset and adjusts the reference voltage automatically.
After completion of the automatic adjustment, the amount of offset measured is saved in the SERVOPACK.
<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 torque analog reference automatically. The mes-sage “NO-OP” indicating that the settings are not appropriate will be displayed, if the following conditions are not met.
• The write prohibited setting (Fn010) must be set to Write permitted (P.0000).
• The servomotor power must be OFF.
Operating Procedure
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 the host controller. Use the manual adjustment of reference offset described in (2) Manual Adjustment of Reference Off-set (Fn00B).
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 torque reference Host
controller
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
MODE/SET DATA/
5.5 Torque Control
5
Operation
(2) Manual Adjustment of Reference Offset (Fn00B)
This mode adjusts the offset by inputting the amount of torque reference offset directly.
Use the manual adjustment of the torque reference offset (Fn00B) in the following cases:
• 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 torque 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 Fn00b.
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 to enable writing. set (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 adjust the amount of off-set.
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.
"Fn00b" 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
5.5.3 Torque Reference Filter
5.5.3 Torque Reference Filter
This smooths the torque reference by applying a first order lag filter to the torque reference (T-REF) input.
Note: A setting value that is too large, however, will slow down response.
Check the response characteristics when setting this parameter.
5.5.4 Speed Limit in Torque Control
This function limits the speed of the servomotor to protect the machine.
A servomotor in torque control is controlled to output the specified torque, but the motor speed is not con-trolled. Therefore, if an excessive reference torque is set for the load torque on the machinery side, the speed of the servomotor may increase greatly. If that may occur, use this function to limit the speed.
Note: The actual limit value of motor speed depends on the load conditions of the servomotor.
The parameters related to the speed limit, such as for selecting the speed limit method, are described next.