The deadtime may be an issue for small sample times. In this case the user may consider the following points to speed-up scans:
ONLINE> set motor/logging off
This reduces the dead time considerably at the cost that motor
positions are no longer logged to /online_dir/motor_positions.bck
.
To re-enable the logging of
the motor positions, use:
ONLINE> set motor/logging on
Motor logging can be enabled/disabled in the scan macros (before, after):
Spectra::gra_command( "set motor_logging on"); Spectra::gra_command( "set motor_logging off");
ONLINE> set exp_to_mw_disable off
Here are some results running CLI Online. Scans are performed from 0 to 0.1 by 0.001, sample time: 0.1, 1 counter. Motor: conversion 5000, slew 50000, acceleration 50000.
acceleration at 50000 set motor_logging on: 33.7 s set motor_logging off: 14.1 s set exp_to_mw_disable on: 13.7 s Update (graphics): 5 13.6 s acceleration to 500000: 12.4 s acceleration to 1000000: 12.2 s acceleration back to 500000 plus Petra-current 13.3 s 4 counters (no petra): 12.5 4 counters, MCA (2048): 24.5 s back to 1 counter sample time to 0.01 3.4 s with dummy motor: 1.1 s
We learn that the overhead time can most efficiently be reduced by disabling the motor logging. In addition we note that an increase of the acceleration can also make an effect.