private void textCountsPerUnit_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e) { if (e.KeyCode == System.Windows.Forms.Keys.Enter) { try { double countsPerUnit = Convert.ToDouble(textCountsPerUnit.Text); if (countsPerUnit > 0) { axis.SetUnit("mm", countsPerUnit); } } catch (Exception ex) { DisplayError("Set Unit error: " + ex.Message); } } }