FKD

Requests/sets value of KD (derivative) LM628 filter parameter for the specified axis[11].

Mnemonic:

Filter KD (KD = derivative constant)

Syntax:

FKD $<$n$>$[, value]

n: Axis number (0:azimuth, 1:elevation).

value: New derivative value (0 to 32767)

Return values:

Success:

FKD 1, n, value

Failure:

FKD 0[, n], err_msg

n: Axis number.

value: New or current derivative value.

err_msg: Should the command fail, this value will be an error message string, explaining the cause of failure. FKD may fail for any of the following reasons:

• The wrong number of parameters were supplied.
• A non-numeric value is provided for any of the parameters.
• The axis number in n is not `0' or `1'.
• The value parameter contains a number that is outside the valid range for the PID filter.

Remarks:

The LM628 PID filters must be properly tuned for the servo systems to work properly. For a detailed discussion on tuning the LM628 PID filter, see ``LM628 Programming Guide (National Semiconductor Application Note 693)''[12]

Example:

     send: FKD 1, 3000
  receive: FKD 1, 1, 3000

     send: FKD 1
  receive: FKD 1, 1, 3000

See also:

FIL, FKI, FKP, FLT, FSI