1. 板卡驱动实现运动暂停/继续功能，板卡动作衔接实现暂停/继续 2. 修复部分调试bug 3. 安全光幕/安全门功能调整

xcd

2020-07-14 0d10528b430721512e0e93e0d455fcec44207ec9

 src/Bro.M071.DBManager/ExcelExportHelper.cs

@@ -107,7 +107,7 @@
                    {
                        // autofit width of cells with small content 
                        ExcelRange columnCells = workSheet.Cells[workSheet.Dimension.Start.Row, columnIndex, workSheet.Dimension.End.Row, columnIndex];
                        int maxLength = columnCells.Max(cell => cell.Value.ToString().Count());
                        int maxLength = columnCells.Max(cell => (cell.Value ?? "").ToString().Count());
                        if (maxLength < 150)
                        {
                            workSheet.Column(columnIndex).AutoFit();
@@ -258,7 +258,7 @@
        {
            try
            {
                return obj.ToString();
                return (obj ?? "").ToString();
            }
            catch (Exception)
            {