➃
Servo Tuning
25
6000 Series Servo Commands
NOTE
The following list contains a brief description of each servo-related 6000 Series command.
More detailed information can be found in the rest of this chapter and within each
command's description in the
6000 Series Software Reference Guide.
Command
Title
Brief Description (detailed descriptions in
6000 Series Software Reference Guide)
SGAF
Acceleration Feedforward Gain
Sets the acceleration feedforward gain in the PIV&F
a
servo algorithm.
SGENB
Servo Gain Set Enable
Enables a previously-saved set of PIV&F gains. A set of gains is saved using the
SGSET
command.
SGI
Set Integral Feedback Gain
Sets the integral gain in the PIV&F servo algorithm.
SGILIM
Set Integral Windup Limit
Sets a limit on the correctional control signal that results from the integral gain action
trying to compensate for a position error that persists too long.
SGP
Proportional Feedback Gain
Sets the proportional gain in the PIV&F servo algorithm.
SGSET
Save a Set of Servo Gains
Saves the presently-defined set of PIV&F gains as a particular
gain set. Up to 5 gain sets
can be saved and enabled at any point in a move profile, allowing different gains at different
points in the profile.
SGV
Set Velocity Feedback Gain
Sets the velocity gain in the PIV&F servo algorithm.
SGVF
Velocity Feedforward Gain
Sets the velocity feedforward gain in the PIV&F
v
servo algorithm.
SMPER
Maximum Allowable Position Error
Sets the maximum allowable error between the commanded position and the actual
position as indicated by the encoder. If the error exceeds this limit, the 6250 shuts down
the motor drive with the Shutdown output. You can enable the
ERROR
command to
continually check for this error condition, and when it occurs to branch to a programmed
response defined in the
ERRORP
program.
SOFFS
Servo Control Signal Offset
Sets an offset to the commanded analog output voltage, which is sent to the drive system.
SSFR
Servo Frequency Ratio
Sets the ratio between the update rate of the move trajectory and the update rate of the servo
action. The intermediate position setpoints calculated by the trajectory generator is updated
at a slower rate then the servo position correction. This command allows you to optimize
this for your application. The default setting (
SSF4
) is sufficient for most applications.
STRGTD
STRGTE
STRGTT
STRGTV
Target Zone Distance
Target Zone Mode Enable
Target Zone Timeout Period
Target Zone Velocity
When using the Target Zone Mode, enabled with the
STRGTE
command, the motor's
actual position and actual velocity must be within the
target zone (that is, within the
distance zone defined by
STRGTD
and within the velocity zone defined by
STRGTV
). If the
motor does not settle into the target zone before the timeout period set by
STRGTT
, the
6250 detects an error.
To prevent subsequent commands/moves from being executed when this error condition
occurs, you must enable the
ERROR
command to continually check for this error
condition, and when it occurs to branch to a programmed response defined in the
ERRORP
program. Otherwise, subsequent commands/moves can be executed regardless of the
motor's actual position and velocity.
This feature is explained in greater detail later in the
Target Zone section.
TDAC
Transfer DAC Voltage
Transfers the voltage output from the 6250's digital-to-analog converter. This is the analog
control signal output at the 6250's CMD terminal.
TGAIN
Transfer Servo Gains
Transfers the currently active set of PIV&F gains. Servo gain sets are established with the
SGSET
command.
TPC
Transfer Position Commanded
Transfers the commanded position (intermediate position setpoint) to the motor.
TPE
Transfer Position of Encoder
Transfers the position of the encoder.
TPER
Transfer Position Error
Transfers the error between the commanded position (
TPC
) and the actual position (
TPE
)
as indicated by the encoder.
TSGSET
Transfer Servo Gain Set
Transfers a previously-saved set of servo gain parameters. A gain set is saved with the
SGSET
command.
TSTLT
Transfer Servo Settling Time
Transfers the time it took the last move to settle within the
target zone (that is, within the
distance zone defined by
STRGTD
and within the velocity zone defined by
STRGTV
). The
Target Zone Mode does not need to be enabled to use this command.