User`s manual

5-24 Motion Mate™ DSM314 for Series 90™-30 PLCs User's Manual – January 2001 GFK-1742A
5
4.17 Torque Limit
.
(0.01 percent) Digital Mode only. The
Torque Limit
Command provides a
method of limiting the torque produced by the GE Fanuc servomotor. The DSM314 will set the
Torque Limit
at the default 10000 (100 %) whenever a power cycle or reset occurs. The PLC
application logic must set any other value for desired
Torque Limit
. The valid range for
Torque
Limit
is 0 to 10000 in units of 0.01%. This represents 0 - 100 % of peak torque at commanded
velocity. If an over-range value of 10001 - 65535 is sent, the torque limit will be set to 10000.
Torque Limit
can be changed during axis motion and takes effect immediately. Refer to the
appropriate servo motor manual for the motor torque curve to determine the actual value of torque
output available at a given velocity. A simple example would be the use of
Torque Limit
to
prevent over-tightening on a machine.
4.18 Set Aux Encoder Position.
(User Units) This command sets the
Actual Position
value for
an Aux Axis Encoder without using a Find Home operation. The
Position Valid
%I bit for the
Aux Axis will be set when the command is received.
4.19 Force Digital Servo Velocity
. (RPM) Digital Mode only. This command bypasses the
position loop and forces a velocity command to the digital servo for tuning purposes. Acceleration
control is not used and changes in velocity take effect immediately. A
Force Digital Servo
Velocity
command value of +4095 will produce a motor velocity of + 4,095 RPM and -4095 will
produce a motor velocity of -4,095 RPM (depending on individual motor maximum velocities).
The digital servo control loops may limit actual motor speed to a lower value. Care should be
taken not to operate a servomotor past the rated duty cycle.
The
Enable Drive
%Q bit must be active with no other motion commanded for the
Force Digital
Servo Velocity
command to operate. The command must remain continuously in the %AQ data
for proper operation. When a Force Digital Servo Velocity command is active for a given axis, any
other %AQ immediate command for that axis will remove the
Force Digital Servo Velocity
data
and halt the servo. Chapter 6, Non-Programmed Motion, also contains information on Force
Digital Servo Velocity.
4.20 Select Return Data 1
.
This command allows alternate data to be reported in the
User
Selected Data 1
%AI location for each axis. The alternate data includes information such as
Parameter memory contents and the DSM314 Firmware Revision.
The
Select Return Data 1
command uses a mode selection and an offset selection. The mode
selection (byte offset +1 of the six byte command) determines the Return Data type. The offset
selection (byte offsets +2, +3 of six-byte command) selects an individual data item for some
modes. Setting the mode to 00h causes the default Torque Command to be reported.
The default
mode and offset for User Selected Data 1 can be set in the module configuration software.
4.21 Select Return Data 2
.
This command allows alternate data to be reported in the
User
Selected Data 2
%AI location for each axis. The alternate data includes information such as
Parameter memory contents and the DSM314 Firmware Revision.
The
Select Return Data 2
command uses a mode selection and an offset selection. The mode
selection (byte offset +1 of the six byte command) determines the Return Data type. The offset
selection (byte offsets +2, +3 of six-byte command) selects an individual data item for some
modes. Setting the mode to 00h causes the default Torque Command to be reported.
The default
mode and offset for User Selected Data 2 can be set in the module configuration software.
The following selections are allowed for Select Return Data 1 and Select Return Data 2: