Aerotech A3200 high precision rotation stage

1. Aerotech A3200 high precision rotation stage Windows based Epics IOC driver implementation Marcel Grunder, EPICS Collaboration Meeting October 2008

2. Aerotech components… ABR1000 Air-Bearing Rot. Stage ATS125 Linear Stage A3200 motion software Ndrive + Npaq Amplifier Marcel Grunder, EPICS Collaboration Meeting October 2008

3. 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

4. A3200 Software Architecture IOC • Layer 4: Windows Apps • Layer 3: Programming Interface • Layer 2: Nmotion SMC engine • Layer 1: Drive Firmware Windows RTX Hardware Ndrive Npaq motors Marcel Grunder, EPICS Collaboration Meeting October 2008

5. At a beamline cryojet exposure box (filter) X-ray beam microscope Marcel Grunder, EPICS Collaboration Meeting October 2008

6. Measurement mode timing diagram Close delay Open delay PSO Open M-Stop angle Shutter Open PSO-Close PSO Open Accl delay 1. calc osc. angle M-Start 2. move Start 3. Det. on 4. move Meas. time time Moving Marcel Grunder, EPICS Collaboration Meeting October 2008

7. 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

8. 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

9. 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

10. 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

11. 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 size static const unsigned stackSizeTable[epicsThreadStackBig+1] = {4000, 6000, 5000000}; • A3200 without hardware behaves differently. • Attention when testing limits, homing, errors… Marcel Grunder, EPICS Collaboration Meeting October 2008