Output Triggers; Triggers On Line-Arc Trajectories - Newport XPS-Q8 Users Manual, Software Tools And Tutorial

XPS-Q8 Controller
13.0

Output Triggers

External data acquisition tools, lasers, and other devices can be synchronized to the
motion. For this purpose, the XPS features one dedicated trigger output per axis, see
Appendix E, PCO connector for details. The XPS can be configured to either output
distance spaced pulses, AquadB encoder signals, or time spaced pulses on this
connector.
In the distance spaced configuration, one output pulse is generated when crossing a
defined position and a new pulse is generated at every defined distance until a
maximum position has been reached. In most cases, this mode provides the most precise
synchronization of the motion to an external tool.
In the AquadB configuration, AquadB encoder signals are output on the PCO
connector. These signals can be provided either always or only if the positioner is
within a defined position window. When used with stages that feature a digital encoder
(AquadB) as opposed to a SinCos encoder (AnalogInterpolated), the AquadB
configuration essentially provides an image of the encoder signals on the PCO
connector.
In the time flasher configuration, an output pulse is generated when crossing a defined
position and a new pulse is generated at a defined time interval until a maximum
position has been reached. In some cases, this mode can provide an even more precise
synchronization of the motion to an external tool, in particular if the variation of the
speed multiplied with the time interval is smaller than the error of the encoder signals
during the same period.
Dedicated hardware is used to check the position crossing and the time interval to attain
less than 50 ns latency between the position crossing and the trigger output.
For the distance spaced pulses configuration, time flasher configuration or AquadB
signals on PCO connector configuration, it is recommended to calibrate the position
compare before all PCO pulses generation. It is also recommended to set the position
compare hardware to the scanning range you intend to use to get the best performances
(refer to Section 13.3 for details).
In addition and independent from the above, the XPS controller can output distance
spaced pulses on Line-arc trajectories and time spaced pulses on PVT trajectories. In
these cases, the distances/time intervals are checked on the servo cycle and a resolution
of 100 µs is provided.
13.1

Triggers on Line-Arc Trajectories

This capability outputs pulses at constant trajectory length intervals on Line-Arc-
Trajectories. The pulses are generated between a start length and an end length. All
lengths are calculated in an orthogonal XY plane. The StartLength, EndLength, and
PathLengthInterval refer to the Setpoint positions.
The trajectory length is calculated at a rate of 8 kHz. This means that the resolution of
the trajectory length is 0.000125 * trajectory velocity. For a trajectory velocity of 100
mm/s for instance, the resolution of the trajectory length is 12.5 µm. If the programmed
PathLengthInterval is not a multiple of this resolution, the pulses can be off from the
ideal positions by a maximum ± half of this resolution.
Two signals are provided:
GPIO2, pin11, Window:
GPIO2, pin12, Pulse:
For details about the XPS I/O connectors, see appendix, section 22.2.
A constant 5 V signal is sent between the StartLength and
the EndLength.
A 1 µs pulse with 5 V peak voltage is sent every
PathLengthInterval.
155 XPSDocumentation V1.4.x (EDH0301En1060 — 10/17)
Motion Tutorial