marcel grunder, epics collaboration meeting october 20081 aerotech a3200 high precision rotation...
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Marcel Grunder, EPICS Collaboration Meeting October 20081
Aerotech A3200 high precision rotation stage
Windows based Epics IOC driver implementation
Marcel Grunder, EPICS Collaboration Meeting October 2008
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Aerotech components…
ABR1000 Air-Bearing Rot. StageATS125 Linear Stage
Ndrive + Npaq Amplifier
A3200 motion software
Marcel Grunder, EPICS Collaboration Meeting October 2008
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Aerotech SMC controller■Motion control system and programming environment ■ Runs on a standard Windows PC■Maximum of 32 intelligent drives connected via IEEE 1394■ 20 kHz servo update rate for all axes ■ Integrated high-speed Position Synchronized Output (PSO) for
position latching.■ Utility Programs to configure, troubleshoot, and operate the
controller■ Programming interfaces include Aerotech’s own AEROBasic or
RS274 G-code, C, C++, VisualBasic, Delphi and LabVIEW
Marcel Grunder, EPICS Collaboration Meeting October 2008
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A3200 Software Architecture
Windows
RTX
Hardware Ndrive Npaq
motors
■ Layer 4: Windows Apps
■ Layer 3: Programming Interface
■ Layer 2: Nmotion SMC engine
■ Layer 1: Drive Firmware
IOC
Marcel Grunder, EPICS Collaboration Meeting October 2008
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At a beamline
X-ray beam
exposure box
(filter)
cryojet
microscope
Marcel Grunder, EPICS Collaboration Meeting October 2008
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Measurement mode timing diagram
Meas. time
osc. angle
time
angle
1. calc
Shutter Open
Open delay
PSO Open
Accl delay
Close delay
PSO-Close
M-Stop
PSO Open
Moving
2. move
3. Det. on4. move
M-Start
Start
Marcel Grunder, EPICS Collaboration Meeting October 2008
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Epics driver requirements
■ Fast signal indicating "movement done"■ A3200 PSO feature used to open/close fast beam shutter ■ Safe homing sequence for multiple axes stages■Measurement mode►Define start + oscillation angle and oscillation time►Use calc records to generate movement start + stop pos, shutter open
+ close pos and velocity.
■ Direct mode►Absolute or incremental move of axis (axes) at defined speed
Marcel Grunder, EPICS Collaboration Meeting October 2008
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Software environment
■ Runs on Windows XP■ EPICS base 3.14.8■ autosave and restore 4-2-1►store offset and velocities
■ state notation language (SNL) 2.0.1►homing sequence
■ A3200 v.2.19
Marcel Grunder, EPICS Collaboration Meeting October 2008
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A3200 programming models
■ Library Programming Model ►Simplest programming model used to initialize controller, to get
controller and motor status info…
■ CNC Programming Model (G code)►compiled and loaded as binary code, directly into the Nmotion SMC
controller.►Runs in RTX real time environment
Marcel Grunder, EPICS Collaboration Meeting October 2008
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A3200 programming models (cont.)
■Mixed Programming Models ►There is no explicit synchronization between the CNC tasks and
Windows threads. ►To synchronize use G-code global variables and CALLBACK
statement.
■ In C: userCallback()►Get the G-code Task number►Set the correct moving flag►scanIoRequest()►epicsEventWaitWithTimeout()
Marcel Grunder, EPICS Collaboration Meeting October 2008
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Difficulties
■ Long time performance was limited by “automatic updates”. Updates done manually while no user operation.
■McAfee Antivirus could disturb long time measurements when McShield service started. McShield will be restarted before user operation starts.
■ A3200 v. > 2.13 requires larger thread stack sizestatic const unsigned stackSizeTable[epicsThreadStackBig+1]
= {4000, 6000, 5000000};
■ A3200 without hardware behaves differently. Attention when testing limits, homing, errors…