PI E-727 User Manual

User Manual
E727T0005, valid for E-727
BRO, 2019-06-28
Physik Instrumente (PI) GmbH & Co. KG, Auf der Roemerstrasse 1, 76228 Karlsruhe, Germany Page 102 / 240
Phone +49 721 4846-0, Fax +49 721 4846-1019, Email info@pi.ws, www.pi.ws
Wave generator output and move commands:
When the wave generator output is active, move commands like MOV or SVA are not allowed for
the associated axis.
See "Control Value Generation" (p. 30) for details.
When the wave generator is to be started by an external trigger signal (WGO bit 1 is set): For
reliable triggering, the pulse width of the input signal has to be at least 2 x the servo update time
of the E-727 (the servo update time is given in seconds by parameter 0x0E000200). The value of
the Wave Multi Start By Trigger parameter (ID 0x13000202) determines if the trigger is enabled
for only one generator start or for multiple starts. See "Wave Generator Started by Trigger Input"
(p. 111) for details and an example.
A wave generator outputs absolute values. In closed-loop operation (servo ON), the output is
interpreted as target positions in either case. In open-loop operation (servo OFF), the
interpretation of the wave generator output depends on the settings of the output matrix (see
"Output Generation" (p. 34) for more information). By default, the matrix is set up so that
commanded open-loop control values numerically correspond to axis position values.
Servo cannot be switched off (SVO) while a wave generator is running for the axis.
As long as a wave generator is running, it is not possible to change (WSL) or to delete (WCL) the
connected wave table (i.e. the waveform). The wave generator table rate (WTR), the number of
output cycles (WGC), the wave offset (WOS) and the output trigger settings (TWS) can be modified
while a wave generator is running.
When a wave generator finishes by running through a specified number of cycles completely, the
final position will be the first point of the waveform, unless the option "start at the endpoint of the
last cycle" was selected. In that case, the final position is the sum of the endpoint of the last output
cycle and any offset defined with WAV for the waveform.
When the wave generator is stopped within an output cycle by command, the axis will remain at
the last output position until a new position is commanded. If the wave generator is then
restarted, it will normally continue with the first point of the waveform, unless started with the
option "start wave generator output triggered by external signal", and the digital input line IN2
(see "Digital I/O Socket" (p. 227)) is used for triggering. In that case, the generator starts with the
first rising edge which is detected on this input line, and it will be stopped when a falling edge is
detected on this line. With the next rising edge, the generator output will continue at the
waveform point where it was stopped.
Wave generator output will continue even if the terminal or the program from which it was started
is quit or if the high voltage output is deactivated.
See the WGO command for more information.
The following data is always lost when the controller is powered down or rebooted:
 Wave table content (WAV)
 Assignment of wave tables to wave generators (WSL)
 Output trigger settings (TWS)
 Number of cycles for wave generator output (WGC)
The following settings can be saved with WPA to non-volatile memory, where they become the
power-on defaults (switch to command level 1 before with the CCL command):
 Wave offset (WOS)
 Wave generator table rate (WTR)

PI E-727 Specifications

General

Brand	PI
Model	E-727
Category	Controller
Language	English