RTC
®
5 PC Interface Board
Rev. 1.9 e
10 Commands And Functions
418
innovators for industry
Delayed Short
List Command
set_encoder_speed
Function
defines the target encoder speed and further parameters for encoder-speed-dependent
automatic laser control.
Call
set_encoder_speed( EncoderNo, Speed, Smooth )
Parameters
EncoderNo
Number of the encoder counter to be used for speed measurement
as an unsigned 32-bit value,
allowed values:
= 0:
Encoder counter Encoder0
= 1:
Encoder counter Encoder1
= 2 and 3: vectorial encoder velocity: a vectorial velocity is calculated
from both encoder speeds (via the pulse rates of both encoder
counters) for use with encoder-speed-dependent automatic
laser control in
Mode
= 5.
Higher bits are ignored.
Speed
Target encoder speed (counter pulse rate) in [counter pulses/ms]
as a 64-bit IEEE floating point value;
allowed range: [100.0 … 16000.0]; for
Speed
> 16000.0,
Speed
is
clipped to 16000.0, for 0.0 <
Speed
< 100.0 to 100.0.
Smooth
Smoothing factor for a 2-stage low-pass filter as a 64-bit IEEE floating
point value; allowed range: [0.0 … 1.0]; larger values will be clipped.
Comments
• If
Smooth
= 0.0, then only the current encoder speed
CurrentSpeed
(based on counter
pulses received in the most recent 10
µ
s) will be used; if
Smooth
= 1.0, then the speed
from the previous clock cycle
PreviousSpeed
. In general, the used speed is:
Speed =
PreviousSpeed
·
Smooth
+
CurrentSpeed
· (1.0 –
Smooth
).
• If
Speed
0.0 or
Smooth
< 0.0, then
set_encoder_speed
will, already during loading,
be replaced by a
return code
RTC5_PARAM_ERROR
).
• One encoder increment results in four counter pulses.
• The maximum value for
(16000.0) corresponds to a counting rate of 16 MHz. The
minimum value for
Speed
(100.0) corresponds to a counting rate of 1/(10
µ
s), i.e. one
counter pulse per output period. Beware of the low resolution of encoder-speed-depen-
dent laser control for low speed values! Encoder-speed-dependent correction is only
recommended if substantially more than one counter pulse per output period (10
µ
s)
are received.
• Also see
"Encoder-Speed-Dependent Laser Control", page 148
.
RTC
®
4
RTC
®
5 new command
Version info
Last change with version DLL 536, OUT 536:
EncoderNo
= 2 and 3
References
,
