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Entry  10 Nov 2017, Frederik Wauters, Bug Report, bug in init of hv class driver 
    Reply  17 Nov 2017, Konstantin Olchanski, Bug Report, bug in init of hv class driver 
    Reply  21 Nov 2017, Stefan Ritt, Bug Report, bug in init of hv class driver 
       Reply  21 Nov 2017, Konstantin Olchanski, Bug Report, bug in init of hv class driver 
Message ID: 1320     Entry time: 10 Nov 2017     Reply to this: 1324   1325
Author: Frederik Wauters 
Topic: Bug Report 
Subject: bug in init of hv class driver 
bug in init
-----------

I used the lv.c class driver, combined with a custom device driver, to control 
our Keithley2611B source meter. This to set negative voltage on Si detectors.

In the 'init' routing, the class driver sets the hv:

  hv_info->demand_mirror[i] = MIN(hv_info->demand[i], hv_info->voltage_limit[i]);

This fails for negative voltage, as it sets the (negative) voltage limit, instead 
of the demand voltage. A simple 'fabs' solves this.

suggestion for 'idle'
---------------------

I let the device do the ramping, not the driver. This also means I have to reset 
the state of the device (current limit) after ramping. The easiest way to to 
this, is using CMD_IDLE of the device driver. This is currently not done in the 
hv.c class driver.
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