Newport MM4006, Руководство пользователя

Страница: 351 / 411

MM4006 F e a t u r e Descriptions Tutorial
NOTE
The starting position and the ending position of the axis must be outside
the interval defined with PB and PE commands without forget accelera-
tion and deceleration ranges.
Example
Generate a signal synchronized b y axis 1. It should start when the axis
crosses position -10 (current units) and end when it reaches position 10.
The step should be 1 (current units).
1PB-10, 1PE10, 1P11 I Defining the signal.
1PA-20 I M o t i o n without any signal generation.
1PS, 1PR40 I M o t i o n with signal generation between position -10 and 10, with a
step of 1 units.
TT I Position reading for each pulse generated.
113R60 I M o t i o n without any signal generation.
NOTE
During a motion with synchronized signal generation, the real and theoreti-
cal position corresponding to each pulse is recorded in the position buffer.
This information can be read back using the TT command. To make the
buffer available and avoid any conflicts, the PS command terminates and
clears any settings made by a TM command. To use the trace mode after a
motion with synchronized signals, the TM command must be re-initiated.
A pulse is generated when the selected axis reaches the specified position,
as follows:
Axis position = PB + (n * PI), where Axis position E [PB... PE].
The position accuracy of the generated pulse (the difference between the
theoretical position PB + n * Pl and the real position) depends on the veloc-
ity of the selected axis as follows:
MaxError =
base * Velocity)/2
Obviously, this value cannot be smaller than the encoder resolution.
Thus, if the calculated MaxError < Encoder resolution,
then M a x E r r o r = Encoder resolution.
Example
For a velocity of 20 mm/sec and Tba, = 300 psec:
MaxError = ± (3 * 104 * 20)/2 = ±3 pm
This pulse location uncertainty will exist for every pulse generated but it is
not cumulative.
NOTE
The pulse location uncertainty is no longer significant if the pulse inter-
val (P1) is set to greater than ten times this error. Thus, the recommend-
ed value for P1 is:
Pimin recommended = 5 * Tbase * Velocity
(%)
ED110181En1020 — 03/03
6.4 N e w p o r t .