diff options
| -rw-r--r-- | device-functions.c | 41 |
1 files changed, 31 insertions, 10 deletions
diff --git a/device-functions.c b/device-functions.c index 47a5bcd..ee62cf1 100644 --- a/device-functions.c +++ b/device-functions.c @@ -735,7 +735,7 @@ int Set_Delay(int check_possible_only,int word_override,int range_override,int c { int word_out; /* what is sent to the DAC */ int cap_range_control; /* what is actually sent to shift register */ - float setting; + float adj_setting, setting, min_one_shot_delay; int point_found,relay_range,UseNegData,entry,actual_pol,dummy; /* abandon if high channel selected by user but not enabled by firmware */ @@ -754,24 +754,45 @@ int Set_Delay(int check_possible_only,int word_override,int range_override,int c } } - setting=set_delay-globals.Flash.propagation_delay[channel]; + /* won't work for all values if apparent fixed delay is less than minimum variable delay */ + min_one_shot_delay = globals.Flash.delay_pwl_time[channel][0][0][0]; + if (globals.Flash.delay_shrink[channel] < min_one_shot_delay) { + return HardwareError; + } + + /* If we need the advance mode for all positive values of delay (for the external trigger + mode to work as expected), then we must have + + ( Flash.delay_shrink - Flash.propagation_delay ) >= min_one_shot_delay + + shrink ~ fixed DDU delay (around 25 ns) + prop ~ propagation delay of main PG - prog delay of SYNC + This is not normally the case, because Flash.propagation_delay can be large. + + If necessary, delay_shrink can be increased by using a larger DDU, or the + propagation_delay difference can be reduced by increasing the delay of the + SYNC pulse. + */ + + /* tweak depending on polarity */ + adj_setting = set_delay; if (globals.ChannelState[channel].amplitude<0.0) { - setting -= globals.Flash.delay_pol_tweak[channel][1]; + adj_setting -= globals.Flash.delay_pol_tweak[channel][1]; } else { - setting -= globals.Flash.delay_pol_tweak[channel][0]; + adj_setting -= globals.Flash.delay_pol_tweak[channel][0]; } - if (setting >= 0.0) { - Set_AdvDel(channel,to_Advance); - } else { + setting = adj_setting + globals.Flash.delay_shrink[channel] - globals.Flash.propagation_delay[channel]; + + if (setting >= min_one_shot_delay) { + Set_AdvDel(channel,to_Advance); + } else { + setting = globals.Flash.delay_shrink[channel] + globals.Flash.propagation_delay[channel] - adj_setting; Set_AdvDel(channel,to_Delay); - setting *= -1; } - setting=setting+globals.Flash.delay_shrink[channel]; - /* protect against impossible settings during first turn-on */ if (setting<zero_equiv_timing) { return HardwareError; |