Fix tcp deadlines.

client.go

@@ -41,6 +41,7 @@ func (m *Mbclient) ReadRegisters(first uint16, numRegs uint16) ([]uint16, error)
 	req[7] = 3 //FunctionCode
 	binary.BigEndian.PutUint16(req[8:10], first-1)
 	binary.BigEndian.PutUint16(req[10:12], numRegs)
+	m.conn.SetDeadline(time.Now().Add(10 * time.Second))
 	byteswritten, err := m.conn.Write(req)
 	if err != nil {
 		return nil, err

client_test.go

@@ -9,6 +9,7 @@ import (
 func TestReadOneRegister(t *testing.T) {
 	c, err := New("192.168.0.154:502", 1)
 	assert.NoError(t, err)
+	for n := 0; n < 5; n++ {
 		res, err := c.ReadRegisters(12401, 2)
 		assert.NoError(t, err)
 		assert.Len(t, res, 2)
@@ -28,5 +29,6 @@ func TestReadOneRegister(t *testing.T) {
 		assert.NoError(t, err)
 		assert.Len(t, res, 1)
 		t.Log(res)
+	}
 
 }