reduce ampl_zero_equiv by a factor of 10 in -LV attenuator modeINSTRUMENT_6_4_27c

1 files changed, 22 insertions, 5 deletions

diff --git a/device-functions.c b/device-functions.c
index 5fd8a98..c864791 100644
--- a/device-functions.c
+++ b/device-functions.c
@@ -1719,7 +1719,7 @@ int Set_Amp_Calib(int channel,float meas_ampl)
 
 	/* use for all channels */
 
-	if (fabs(globals.ChannelState[channel].amplitude)<globals.Flash.ampl_zero_equiv[channel]) {
+	if (fabs(globals.ChannelState[channel].amplitude) < get_ampl_zero_equiv(channel)) {
 		return NeedNonZeroAmpl;
 	}
 
@@ -2872,12 +2872,12 @@ int Set_VI_Control(int parameter,int channel,float new_ampl)
 			}
 
 			/* clamping distortion below "zero equiv" amplitude */
-			if (ampl_for_distort_calc < globals.Flash.ampl_zero_equiv[channel]) {
-				ampl_for_distort_calc = globals.Flash.ampl_zero_equiv[channel];
+			if (ampl_for_distort_calc < get_ampl_zero_equiv(channel)) {
+				ampl_for_distort_calc = get_ampl_zero_equiv(channel);
 			}
 
 			/* prohit values of Y that would cause divide-by-zero error */
-			if ( (-globals.Flash.distort_Y[channel]) > globals.Flash.ampl_zero_equiv[channel]) {
+			if ( (-globals.Flash.distort_Y[channel]) > get_ampl_zero_equiv(channel)) {
 				return PW_Distort_Error;
 			}
 
@@ -4975,7 +4975,7 @@ float rst_ampl_value (int channel)
 
 		// For AVRQ -AHV, -XHV options, where valids ampls may be
 		// 1.0 to 1.5 kV, positive or negative
-		return globals.Flash.ampl_zero_equiv[channel];
+		return get_ampl_zero_equiv(channel);
 
 	} else if (max == 0) {
 
@@ -5058,3 +5058,20 @@ void get_min_max_fixed_ampls (int channel, float *min_ampl, float *max_ampl) {
 		if (use_ampl < *min_ampl) *min_ampl = use_ampl;
         }
 }
+
+
+float get_ampl_zero_equiv(int channel)
+{
+	float result;
+	result = globals.Flash.ampl_zero_equiv[channel];
+
+	if (globals.Flash.switchable_zout[channel]
+		&& attenuator_count(channel)
+		&& (globals.ChannelState[channel].zout==globals.Flash.zout_max[channel]) ) {
+
+		// lower min equiv ampl if attenuators are in use in -LV units */
+		result /= 10.0;
+	}
+
+	return result;
+}