TC Statement
Returns the torque control mode setting and current mode.
Syntax
(1) TC { On | Off }
(2) TC
Parameters
- On | Off
-
- On : Torque control mode ON
- Off : Torque control mode OFF
Return Values
When the parameter is omitted, returns the current torque control mode.
Description
TC On/Off set the torque control mode available/unavailable.
The torque control mode sets the motor output limit to generate the constant force. This is used in pressing a hand to an object at constant force or making the close contact and coordinate moving of hand with an object .
Before setting the torque control available, configure the limits of torque control in TCLim.
Under the torque control, the robot moves as positioning to the target while an operation command is executed. When the robot contact an object and motor output is at the torque control limit, the robot stops its operation and keeps the constant torque.
In any of the following cases, the torque mode turns unavailable.
- Controller Startup
- Motor On
- SFree, SLock, Brake
- Reset or Reset Error is executed
- Task end by STOP switch or Quit All
See Also
TCLim, TCSpeed
TC Statement Example 1
Speed 5
Go ApproachPoint
'Set the Z axis torque limit to 20.
TCLim -1, -1, 20, -1
TC On
Go TargetPoint
Wait 3
Go ApproachPoint
TC Off
Notes
When a position error detected on Safety Board mounted controller
Change the program so that “current position of the robot” and “current target position of the robot” are not far apart.
If they are far apart, the Safety Board detects failure, and “Erorr No.9801 Detected a position error by the Safety Board.” error occurs. (Only for controllers mounting the Safety Board.)
The current position of the robot can be required by RealPos function.
The current target position of the robot can be required by CurPos function.
When using SCARA robot, it is recommended that the difference between RealPos and CurPos be less than about J1:10 deg., J2:10 deg., J3:40 mm, and J4:90 deg.
The value that causes an error differs depending on the model. It can be set for each model within a range that does not cause an error.
Speed limiting using TCSpeed makes a gap between RealPos and CurPos before contacting the target object. Do not use TCSpeed, or if you want to use it, be sure that the value is the same as Speed.
 |  |
| 1. When not contacting the target object | 2. When contacting the target object |
| Symbol | Description |
|---|---|
| a | Hand |
| b | Target object |
The current position of the robot (RealPos) and the current target position of the robot (CurPos) are close.
The current position of the robot (RealPos) maintains the position where the hand contacted the target object.
The current target position of the robot (CurPos) moves toward TagetPoint.
If this distance exceeds a certain amount, error No.9801 will occur.
The following shows a sample of code without occurrence of position error of Safety Board.
With using Till statement, errors can be avoided by proceeding to the next process when the difference between the “current position of the robot” and the “current target position of the robot” is greater than or equal to a certain amount.
It makes cycle time shorter by making the difference as small as possible, it can move on to the next process early.
TC Statement Example 2
Speed 5
Go ApproachPoint
'Set the Z axis torque limit to 20
TCLim -1, -1, 20, -1
Xqt posDiffChk(10.0) 'Starts a task of checking for position differences. Sets a flag if J3 has 10.0 mm or more gap.
TC On
Go TargetPoint Till MemSw(0)
Wait 3
Go ApproachPoint
TC Off
Function posDiffChk(Zth As Double)
Do
If (Abs(CZ(RealPos) - CZ(CurPos)) > Zth) Then
'Did the difference between "current position of the robot" and "current target position of the robot" exceed the threshold ?
MemOn (0) ' Position deviation is large, Flag ON
Else
MemOff (0) ' Position deviation is large, Flag clear
EndIf
Wait 0.01
Loop
Fend