Delta Tau GEO BRICK LV 사용자 설명서

In addition to the normal following error protection provided by the Ixx11 variable for each motor, Turbo 
PMAC can shut down the motor if the time-integrated value of the following error exceeds a preset value.  
This integrated error feature can protect against those cases in which the magnitude of the measured 
following error never gets very large – for example, a loss of feedback followed by a very short 
commanded move. 

Turbo PMAC performs the integrated following error check only if the Ixx63 integration limit parameter 
is less than zero.  When this is the case, the magnitude of Ixx11 is used for the normal unintegrated 
following error check.  In addition, the value of the PID integrator is compared against the Ixx63 
integration limit magnitude.  If the integrator value has saturated at +/-Ixx63 (the limiting function in the 
PID loop will not let it exceed this value), then Turbo PMAC will trip (kill) this motor on an integrated 
following error fault, just as it would for a normal following error fault. 

For the integrated following error limit to be effective, the Ixx33 integral gain must be greater than zero, 
and preferably set as high as can be tolerated.  Also, the Ixx34 integration mode parameter must be set to 
0, so that the integrator is on during programmed moves.   

Remember that the integrator stops increasing in magnitude if the command output has saturated at Ixx69.  
The magnitude of Ixx63 must be small enough that it will trip before the output saturates.  The magnitude 
of Ixx63 that would cause output saturation at Ixx69 from the integrator alone is: 













∗

∗

=

 

The magnitude of Ixx63 must be less than this value for the shutdown function to be effective.  
Remember that there will be other components to the output, for instance from the proportional gain.  
With a bare motor, test to see that this limit can trip the motor reliably. 

When a motor is killed due to integrated following error fault, the standard following error fault motor 
status bit is set.  In addition, a separate integrated following error fault motor status bit is set.  Both bits 
are cleared when the motor is re-enabled. 

Turbo PMAC has both hardware and software overtravel position limit features.  These are intended to 
prevent motion accidentally commanded out of the legal range of positions. 

The axis-interface circuitry associated with each servo interface channel in a Turbo PMAC system has 
positive and negative hardware overtravel limit switch inputs.  The exact nature of this input circuitry and 
instructions for connecting the limit switches are described in the Hardware Reference Manual for each 
Turbo PMAC and axis-interface accessory. 

Generally, these inputs are optically isolated, with a failsafe circuit design.  The limit switches must be 
normally closed, conducting current through the opto-isolator when the axis is not in the limit.  This 
conducting condition produces a zero state in the flag register for the channel in the Servo IC; the 
processor must read this zero to permit motion in that direction. 

Anything that stops current from flowing through the opto-isolator, whether from actually hitting the 
limit, from cable disconnection, or from loss of power supply for the limit circuit, produces a one state in 
the Servo IC.  When the processor sees this, it will not permit motion in that direction.