How can I solve storage SQL Server speed

I'm working on system that detects RFID tags and stores its information into a SQL Server database.

When I tried to execute my app an exception shows up:

The data in the string or binaries will be truncated.
The instruction has been stopped.

I think that my problem is that the SQL Server database can't store a high number of tags in one second.

RQ: I'm using JT-928 4 Channel UHF RFID reader (it can read 300tag/second)

Mycode is:

no++;
//   labelCount.Text = (int.Parse(labelCount.Text) + 1).ToString(); // 更新读取次数
labelTagCount.Text = Tag_data.Count.ToString();// 更新标签计数

ListViewItem lvi = new ListViewItem();
lvi.Text = (lvTagData.Items.Count + 1).ToString();
lvi.SubItems.Add(apcData.epc);
lvi.SubItems.Add(apcData.count.ToString());
lvi.SubItems.Add(apcData.antNo.ToString());
lvi.SubItems.Add(apcData.devNo);
lvi.SubItems.Add(apcData.IP);
lvTagData.Items.Add(lvi);

missingtimer.Start();
continuscheck(apcData.epc, apcData.antNo.ToString());

And continuscheck :

string sqlcode1 = @"INSERT INTO [dbo].[missingelemets] ([RFID],[Chanel])
                    VALUES ('" + RFID + "','" + chanel + "')";

SqlConnection con2 = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["UR2k_CS.Properties.Settings.StoreConnectionString"].ConnectionString);
con2.Open();

SqlCommand c1 = new SqlCommand(sqlcode1, con2);

c1.ExecuteNonQuery();// exception Instruction
con2.Close();

Thanks for help