Cmd |
Parameters |
Description |
Notes |
0x0 (Rotate slow) 0x1 (Rotate fast) |
speed [24 bits, 2's comp, 16.8 FP format]
(A->M) |
Rotate the motor at the specified rate. The
rate
is a 24-bit 2's complement number of motor ticks per 6.5 ms period in a
16.8 fixed point fractional format |
The protocol assumes
that the autostar and motor act as a closed loop. The changes can be
seen as the autostar converges on a sidereal tracking speed. |
0x3 (Set LED current) |
led value [8 bits] (A->M) |
Sets the LED current used for the encoder LED. |
This is stored in the Autostar and sent at initialization. |
0x4 (Calibrate LED) |
None |
Tells the motor to determine the optimal LED
current for the optical encoder |
Unknown whether it uses this value, or whether
it needs to be read and written to take effect. |
0x5 (Stop) | None | Stop the motor | The motor may continue to rotate for a short time after this command is issued |
0x6 (Full speed reverse) |
None |
Rotate the motor at the highest possible speed
in the negative direction |
|
0x7 (Full speed forward) |
None |
Rotate the motor at the highest possible speed
in the negative direction |
|
0x8 (Read status) |
relative position change [16 bits, 2's comp], PWM duty cycle [8 bits], encoder error [1 bit] (M -> A) |
Read information about the position and
activity
of the motor. The position is reset after this command |
If the PWM value is 0xff and the position change
is
zero then it is likely that the motor is stalled |
0x9 (Get LED current) |
led value [8 bits] (M->A) |
Get the LED current. |
Issued after the calibrate LED command |
0xb (Get motor type) |
motor type [8 bits] (M->A) |
Get the type of motor attached |
The DH motors returns 0x10. Larger values
cause
the #494 autostar to indicate the ETX Autostar should be used. |
0xe4 (unknown) | None | Unknown. Used by the autostar after the stop command when performing LED calibration. parking the scope, or sleeping the scope | Doesn't seem to clear the status information. |
0x2 (Set error count) |
error [16 bits] (A -> M) |
Add the specified error to the current
position error. The servo loop will try to compensate |
This is used by the pulseguide commands to
nudge the scope position. For the #497 it's also used to nudge the
scope
to the correct position after GOTO in some cases. |