Page History
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silke says: "usb4" relative encoder reader can go up to 15MHz5MHz, but maybe not enough space in the vacuum environment. alex found another renishaw that goes up to 15MHz.
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ankush encoder document: https://docs.google.com/document/d/1Ho1IpT4903wkUoJMV06z5hou9to5CfAgtJBDPdBl6I4/edit?ts=600b806d
→ (Silke) this lists the USB version of the encoder we originally used the PCI version for. We now have a box as Ankush laid out, except that it 'splits' the signal, so has in&out for each encoder channel. This device its listed towards the end of Supported Control & DAQ Devices
Matt says we may have an existing board that could do the readout/timestamping
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- 10kHz with interpolation?
- multiple encoders?
- combine absolute/relative (may be complexity issues)
- 2 staggered slower encoders
- need fpga timestamping
- 100 microev resolution requirement
Option max rate work to be done drawbacks/other consideration A absolute encoder used for relevant stage 10-20(?) kHz controls: rework PLC to send data (current solution likely ~1kHz)
DAQ: likely FPGA timestamping
B absolute encoder used for relevant stage,
interleave with second absolute encoder
20-40 kHz as above need to ensure both encoders read back equivalent data,
intersperse jitter from both?, same latency
C add a relative quadrature encoder on shaft 5 or more MHz DAQ: need board to read signal & timestamp complicated and possible not very reproducible mapping of measured &
relevant motion
D add a relative quadrature encoder in vacuum 5 or more MHz DAQ: need board to read signal & timestamp
engineering: figure out how to add relative encoder
To do
- fill out the table options and costs (alex and silke)
- talk to mechanical engineers (Georgi)
- meet in two weeks
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