AXS

The AXS command requests that a ZY return status word for the specified LM628 axis motion controller.

Mnemonic:

AXis Signals register

Syntax:

AXS $<$n$>$

n: axis number (0:azimuth or 1:elevation)

Return values:

Success:

AXS 1, n, sw

Failure:

AXS 0, err_msg

n: Axis number

sw: LM628 16-bit status word, in hexadecimal. See remarks below for the significance of the bits.

err_msg: Should the command fail, this value will be an error message string, explaining the cause of failure.

Remarks:

The status word will be returned as a 16 bit hexadecimal number. The 16 bits have the following meaning:

bit	Description
Bit 15	Host Interrupt
Bit 14	Acceleration Loaded (But Not Updated)
Bit 13	UDF Executed (But Filter Not Yet Updated)
Bit 12	Forward Direction
Bit 11	Velocity Mode
Bit 10	On Target
Bit 9	Turn Off Upon Excessive Position Error
Bit 8	Eight-Bit Output Mode
Bit 7	Motor Off
Bit 6	Breakpoint Reached
Bit 5	Excessive Position Error
Bit 4	Wraparound Occurred
Bit 3	Index Pulse Acquired
Bit 2	Trajectory Complete
Bit 1	Command Error
Bit 0	Acquire Next Index

For a full explanation of these flags, see the National Semiconductor LM628 data sheet[11].

Example:

     send: AXS 0
  receive: AXS 1, 0, 0x0604

See also:

AXIS, STS, STW