diff --git a/app/tests/test_infos.py b/app/tests/test_infos.py
index c3e6ddf..4b23bfb 100644
--- a/app/tests/test_infos.py
+++ b/app/tests/test_infos.py
@@ -17,13 +17,13 @@ def test_statistic_counter():
     assert val == None or val == 0
 
     i.static_init()                # initialize counter
-    assert json.dumps(i.stat) == json.dumps({"proxy": {"Inverter_Cnt": 0, "Unknown_SNR": 0, "Unknown_Msg": 0, "Invalid_Data_Type": 0, "Internal_Error": 0,"Unknown_Ctrl": 0, "OTA_Start_Msg": 0, "SW_Exception": 0, "Invalid_Msg_Format": 0, "AT_Command": 0, "Modbus_Command": 0}})
+    assert json.dumps(i.stat) == json.dumps({"proxy": {"Inverter_Cnt": 0, "Unknown_SNR": 0, "Unknown_Msg": 0, "Invalid_Data_Type": 0, "Internal_Error": 0,"Unknown_Ctrl": 0, "OTA_Start_Msg": 0, "SW_Exception": 0, "Invalid_Msg_Format": 0, "AT_Command": 0, "AT_Command_Blocked": 0, "Modbus_Command": 0}})
                                             
     val = i.dev_value(Register.INVERTER_CNT)  # valid and initiliazed addr
     assert val == 0
 
     i.inc_counter('Inverter_Cnt')
-    assert json.dumps(i.stat) == json.dumps({"proxy": {"Inverter_Cnt": 1, "Unknown_SNR": 0, "Unknown_Msg": 0, "Invalid_Data_Type": 0, "Internal_Error": 0,"Unknown_Ctrl": 0, "OTA_Start_Msg": 0, "SW_Exception": 0, "Invalid_Msg_Format": 0, "AT_Command": 0, "Modbus_Command": 0}})
+    assert json.dumps(i.stat) == json.dumps({"proxy": {"Inverter_Cnt": 1, "Unknown_SNR": 0, "Unknown_Msg": 0, "Invalid_Data_Type": 0, "Internal_Error": 0,"Unknown_Ctrl": 0, "OTA_Start_Msg": 0, "SW_Exception": 0, "Invalid_Msg_Format": 0, "AT_Command": 0, "AT_Command_Blocked": 0, "Modbus_Command": 0}})
     val = i.dev_value(Register.INVERTER_CNT)
     assert val == 1
 
diff --git a/app/tests/test_solarman.py b/app/tests/test_solarman.py
index 52a66a8..06a57f0 100644
--- a/app/tests/test_solarman.py
+++ b/app/tests/test_solarman.py
@@ -39,9 +39,10 @@ class MemoryStream(SolarmanV5):
         self.addr = 'Test: SrvSide'
         self.db.stat['proxy']['Invalid_Msg_Format'] = 0
         self.db.stat['proxy']['AT_Command'] = 0
+        self.db.stat['proxy']['AT_Command_Blocked'] = 0
         self.test_exception_async_write = False
         self.entity_prfx = ''
-        self.at_acl = {'mqtt': {'allow': ['AT+'], 'block': []}, 'tsun': {'allow': ['AT+Z', 'AT+UPURL', 'AT+SUPDATE', 'AT+TIME'], 'block': []}}
+        self.at_acl = {'mqtt': {'allow': ['AT+'], 'block': ['AT+WEBU']}, 'tsun': {'allow': ['AT+Z', 'AT+UPURL', 'AT+SUPDATE', 'AT+TIME'], 'block': ['AT+WEBU']}}
 
     def _timestamp(self):
         return timestamp
@@ -466,6 +467,15 @@ def AtCommandIndMsg():  # 0x4510
     msg += b'\x15'
     return msg
 
+@pytest.fixture
+def AtCommandIndMsgBlock():  # 0x4510
+    msg  = b'\xa5\x17\x00\x10\x45\x03\x02' +get_sn() +b'\x01\x02\x00'
+    msg += b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'           
+    msg += b'AT+WEBU\r'
+    msg += correct_checksum(msg)
+    msg += b'\x15'
+    return msg
+
 @pytest.fixture
 def AtCommandRspMsg():  # 0x1510
     msg  = b'\xa5\x0a\x00\x10\x15\x03\x03' +get_sn()  +b'\x01\x01'
@@ -1277,11 +1287,49 @@ async def test_AT_cmd(ConfigTsunAllowAll, DeviceIndMsg, DeviceRspMsg, InverterIn
     assert m.forward_at_cmd_resp == False
     m.close()
 
-def test_at_command_ind(ConfigTsunInv1, AtCommandIndMsg):
+@pytest.mark.asyncio
+async def test_AT_cmd_blocked(ConfigTsunAllowAll, DeviceIndMsg, DeviceRspMsg, InverterIndMsg, InverterRspMsg, AtCommandIndMsg):
+    ConfigTsunAllowAll
+    m = MemoryStream(DeviceIndMsg, (0,), True)
+    m.append_msg(InverterIndMsg)
+    m.read()
+    assert m.control == 0x4110
+    assert str(m.seq) == '01:01'
+    assert m._recv_buffer==InverterIndMsg   # unhandled next message
+    assert m._send_buffer==DeviceRspMsg
+    assert m._forward_buffer==DeviceIndMsg
+
+    m._send_buffer = bytearray(0) # clear send buffer for next test    
+    m._forward_buffer = bytearray(0) # clear send buffer for next test    
+    await m.send_at_cmd('AT+WEBU')
+    assert m._recv_buffer==InverterIndMsg   # unhandled next message
+    assert m._send_buffer==b''
+    assert m._forward_buffer==b''
+    assert str(m.seq) == '01:01'
+
+    m.read()
+    assert m.control == 0x4210
+    assert str(m.seq) == '02:02'
+    assert m._recv_buffer==b''
+    assert m._send_buffer==InverterRspMsg
+    assert m._forward_buffer==InverterIndMsg
+    
+    m._send_buffer = bytearray(0) # clear send buffer for next test    
+    m._forward_buffer = bytearray(0) # clear send buffer for next test    
+    await m.send_at_cmd('AT+WEBU')
+    assert m._recv_buffer==b''
+    assert m._send_buffer==b''
+    assert m._forward_buffer==b''
+    assert str(m.seq) == '02:02'
+    assert m.forward_at_cmd_resp == False
+    m.close()
+
+def test_AT_cmd_ind(ConfigTsunInv1, AtCommandIndMsg):
     ConfigTsunInv1
     m = MemoryStream(AtCommandIndMsg, (0,), False)
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['AT_Command'] = 0
+    m.db.stat['proxy']['AT_Command_Blocked'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
     m.read()         # read complete msg, and dispatch msg
     assert not m.header_valid  # must be invalid, since msg was handled and buffer flushed
@@ -1297,6 +1345,32 @@ def test_at_command_ind(ConfigTsunInv1, AtCommandIndMsg):
     assert m._forward_buffer==AtCommandIndMsg
     assert m.db.stat['proxy']['Invalid_Msg_Format'] == 0
     assert m.db.stat['proxy']['AT_Command'] == 1
+    assert m.db.stat['proxy']['AT_Command_Blocked'] == 0
+    assert m.db.stat['proxy']['Modbus_Command'] == 0
+    m.close()
+
+def test_AT_cmd_ind_block(ConfigTsunInv1, AtCommandIndMsgBlock):
+    ConfigTsunInv1
+    m = MemoryStream(AtCommandIndMsgBlock, (0,), False)
+    m.db.stat['proxy']['Unknown_Ctrl'] = 0
+    m.db.stat['proxy']['AT_Command'] = 0
+    m.db.stat['proxy']['AT_Command_Blocked'] = 0
+    m.db.stat['proxy']['Modbus_Command'] = 0
+    m.read()         # read complete msg, and dispatch msg
+    assert not m.header_valid  # must be invalid, since msg was handled and buffer flushed
+    assert m.msg_count == 1
+    assert m.header_len==11
+    assert m.snr == 2070233889
+    # assert m.unique_id == '2070233889'
+    assert m.control == 0x4510
+    assert str(m.seq) == '03:02'
+    assert m.data_len == 23
+    assert m._recv_buffer==b''
+    assert m._send_buffer==b''
+    assert m._forward_buffer==b''
+    assert m.db.stat['proxy']['Invalid_Msg_Format'] == 0
+    assert m.db.stat['proxy']['AT_Command'] == 0
+    assert m.db.stat['proxy']['AT_Command_Blocked'] == 1
     assert m.db.stat['proxy']['Modbus_Command'] == 0
     m.close()