fscan
Description
fscan is a continuous scan of one motor. The real motor start position is computed so that the motor can reach its desired velocity at requested start_pos. Acquisition starts at that position when the motor is at constant speed.
fscan supports three scanning mode:
- TIME : first trigger in position, next ones in time
- POSITION : all triggers are in position
- CAMERA : (only when using one lima device) first trigger in position, then all counters follow camera image acquisition.
By default, lima devices are set to EXTERNAL_TRIGGER_MULTI mode and all other synchronized devices (mca, p201, ...) are used in GATE mode, generated in TIME. Alternatively, the parameter gate_mode can bet set to POSITION. In that case, start and end of the gate are generated using motor position and all devices, including lima ones, are programmed in GATE mode.
The camera readout time can be handled in two ways:
- by setting step_time : this will fix the time between two image start triggers.
- by setting step_time=0. : fscan will sum estimated camera readout time and latency_time to define the real step_time.
Parameters
| parameter | description | |
|---|---|---|
| motor | bliss motor object (not motor name string !!) | |
| start_pos | start position of first acquisition | |
| step_size | step size in position of one acquisition | |
| step_time | [sec] | if set to non-zero, fix time between start triggers |
| acq_time | [sec] | acquisition time per point |
| npoints | total number of points | |
| scan_mode | TIME,POSITION,CAMERA | scanning mode |
| gate_mode | TIME,POSITION | gate mode used while scanning mode is in POSITION. |
| camera_signal | EDGE,LEVEL | input camera signal type when in CAMERA mode. |
| latency_time | [sec] | additionnal latency time added to detector readout time |
Common parameters implemented: save_flag, display_flag, sync_encoder, home_rotation, acc_margin, sampling_time.