HCTL-1100 Datasheet, PDF (32/39 Pages) Agilent(Hewlett-Packard) – General Purpose Motion Control ICs

The command and actual velocity
are 16-bit two’s-complement
words.
The command velocity resides in
registers R24H (MSB) and R23H
(LSB). These registers are
unlatched which means that the
command velocity will change to
a new velocity as soon as the
value in either R23H or R24H is
changed. The registers can be
read or written to in any order.
R24H
R23H
IIII IIII IIII FFFF
COMMAND VELOCITY FORMAT
The units of velocity are quadra-
ture counts/sample time. To
convert from rpm to quadrature
counts/sample time, use the
formula shown below:
Vq = (Vr)(N)(t)(0.01667/rpm-sec) [9]
Where:
Vq = velocity in quadrature
counts/sample time
Vr = velocity in rpm
N = 4 times the number of slots
in the codewheel (i.e.,
quadrature counts).
t = The HCTL-1100 sample time
in seconds. (See the section on
the HCTL-1100’s Sample Timer
register).
Because the Command Velocity
registers (R24H and R23H) are
internally interpreted by the
HCTL-1100 as 12 bits of integer
and 4 bits of fraction, the host
processor must multiply the
desired command velocity (in
quadrature counts/sample time)
by 16 before programming it into
the HCTL-1100’s Command
Velocity registers.
The actual velocity is computed
only in this algorithm and stored
in scratch registers R35H (MSB)
and R34H (LSB). There is no
fractional component in the actual
velocity registers and they can be
read in any order.
The controller tracks the com-
mand velocity continuously until
new mode command is given. The
system behavior after a new
velocity command is governed
only by the system dynamics until
a steady state velocity is reached.
Integral Velocity Mode
Flags: F0 Cleared
F3 Cleared
F5 Set to begin move
Registers Used:
Register
Function
R00H R00D Flag Register
R26H R38D Acceleration LSB
R27H R39D Acceleration MSB
R3CH R60D Command
Velocity
Integral Velocity Control performs
continuous velocity profiling
which is specified by a command
velocity and command accelera-
tion. Figure 13 shows the capabil-
ity of this control algorithm.
The user can change velocity and
acceleration any time to con-
tinuously profile velocity in time.
Once the specified velocity is
reached, the HCTL-1100 will
maintain that velocity until a new
command is specified. Changes
between actual velocities occur at
the presently specified linear
acceleration.
The command velocity is an 8-bit
two’s-complement word stored in
R3CH. The units of velocity are
Example Code for Programming Proportional Velocity Mode
{ Begin }
Hard Reset { HCTL-1100 goes into INIT/IDLE Mode }
Initialize Filter, Timer, Command Position Registers
Write 03H to Register R05H
{ HCTL-1100 is now in Position Mode }
Write Desired Command Velocity (if needed)
Set Flag F3 {Proportional Velocity Move Begins}
{ System ramps to Command Velocity }
2-170
Continue writing new Command Velocities
{end}