SV4401A V0.7.3 固件特性：

1.参考迹线功能优化，Tr1~Tr4增加数据保存到内存功能：
  (a).长按对应的迹线控制框弹出快捷菜单，选择【数据->内存】存储当前数据；
  (b).可通过菜单【显示/关闭内存迹线】开启或关闭内存迹线；
  (c).可通过菜单【数学计算】将当前数据与内存数据进行计算(计算发生在数据格式化之前)，计算的结果显示为数据迹线。
  (d).保存到内存中的数据，可随校准文件保存和回调。
2.新增两种标记信息显示类型（“DATA & MEM”和“DATA & ΔY(DATA,MEM)”，对于史密斯圆图和极坐标，“DATA & ΔY(DATA,MEM)”等同于“DATA & MEM”)，可在标记信息设置对话框中选择显示类型。
3.新增增量显示模式，可通过设置参考标记，自动计算当前标记与参考标记的频率以及响应值的差值(史密斯以及极坐标格式下，显示原始数据)。
4.新增频标辅助线功能，用于定位内存迹线与主迹线的频率标记和差异值。
5.修复了因中频增益切换引起的S21群时延数据异常。
6.【激励】菜单下新增【分析功能】子菜单，将【L/C匹配】和【扫描分析】移动至【分析功能】菜单下。
7.新增极限测试功能，菜单路径：【激励】->【分析功能】->【极限测试】。



SV4401A firmware V0.7.3 features:

1. The reference trace feature is modified to memory data trace:
  (a). Long press the corresponding 'trace control box' to call up quick menu, and press [Data -> MEM] to store data to memory;
  (b). Press [Show/Close MEM trace] to show or close the memory trace;
  (c). Press [Math] to perform mathematical calculation with the current data and the memory data (the calculation occurs before the data is formatted), and the results will be displayed with the data trace;
  (d). The memory data can be saved or recalled along with the cal file.

2. Two new marker info types added ('DATA & MEM' and 'DATA & ΔY(DATA,MEM)', for smith and polar chart, 'DATA & ΔY(DATA,MEM)' is equivalent to 'DATA & MEM'), which can be set in the [INFO SET] dialog. Menu path: [MARKER] -> [INFO SET].

3. New feature of incremental value display, which will show the difference in frequency and trace data between the current marker and the reference marker by set a reference marker (not available for smith and polar chart).

4. New feature of marker auxiliary line, which is used to locate the frequency markers and differences between the data trace and the memory trace. Turn on 'MKR AUX LINE' in the [INFO SET] dialog to enable marker auxiliary line.

5. Fixed the bug with S21 group delay caused by IF gain switching.

6. [L/C MATCH] and [SWEEP ANALYSIS] are moved to [STIMULUS] -> [ANALYSIS].

7. New feature of 'Limit test'. Menu path: [STIMULUS] -> [ANALYSIS] -> [LIMIT TEST].








