Figure out x/y once and for all!

[djsperka]

Need to get x/y fixed up. Gather notes&verify&record this all in one place for easy reference.

1. Fast axis = ? Slow axis=?
2. ao0 = ?, ao1=?
3. Scan configuration labels
4. Etc config galvo labels
5. Check and label BNC from NI box to galvo
6. Add to docs

[djsperka]

Using oscilloscope, determined the following:

In code, when configuring DAQ galvo stuff (VtxBaseEngine), the "galvo_x_device_channel" is the first AnalogVoltageOutput created, and it ends up being the SLOW AXIS.

For example, I have config set so that x_device is 'Dev1/ao0'. This is routed to galvobox->"Y". On our raster plots, this shows up as the x-axis.

xAVO = daqmx.AnalogVoltageOutput(cfg.galvo_x_device_channel, cfg.galvo_x_units_per_volt, Block.StreamIndex.GalvoTarget, 0)
xAVO.limits = cfg.galvo_x_voltage_range
ioc_out.channels.append(xAVO)
yAVO = daqmx.AnalogVoltageOutput(cfg.galvo_y_device_channel, cfg.galvo_y_units_per_volt, Block.StreamIndex.GalvoTarget, 1)
yAVO.limits = cfg.galvo_y_voltage_range
ioc_out.channels.append(yAVO)