diff --git a/app/tests/test_solarman.py b/app/tests/test_solarman.py
index b1d0a04..e339412 100644
--- a/app/tests/test_solarman.py
+++ b/app/tests/test_solarman.py
@@ -1277,7 +1277,6 @@ async def test_AT_cmd(ConfigTsunAllowAll, DeviceIndMsg, DeviceRspMsg, InverterIn
 def test_at_command_ind(ConfigTsunInv1, AtCommandIndMsg):
     ConfigTsunInv1
     m = MemoryStream(AtCommandIndMsg, (0,), False)
-    m.forward_modbus_resp = False
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['AT_Command'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
@@ -1296,7 +1295,6 @@ def test_at_command_ind(ConfigTsunInv1, AtCommandIndMsg):
     assert m.db.stat['proxy']['Invalid_Msg_Format'] == 0
     assert m.db.stat['proxy']['AT_Command'] == 1
     assert m.db.stat['proxy']['Modbus_Command'] == 0
-    assert m.forward_modbus_resp == False
     m.close()
 
 def test_msg_at_command_rsp1(ConfigTsunInv1, AtCommandRspMsg):
@@ -1342,7 +1340,6 @@ def test_msg_modbus_req(ConfigTsunInv1, MsgModbusCmd):
     m = MemoryStream(b'')
     c = m.createClientStream(MsgModbusCmd)
 
-    m.forward_modbus_resp = False
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['AT_Command'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
@@ -1360,7 +1357,6 @@ def test_msg_modbus_req(ConfigTsunInv1, MsgModbusCmd):
     assert m.db.stat['proxy']['AT_Command'] == 0
     assert m.db.stat['proxy']['Modbus_Command'] == 1
     assert m.db.stat['proxy']['Invalid_Msg_Format'] == 0
-    assert m.forward_modbus_resp == True
     m.close()
 
 def test_msg_modbus_req2(ConfigTsunInv1, MsgModbusCmdCrcErr):
@@ -1368,7 +1364,6 @@ def test_msg_modbus_req2(ConfigTsunInv1, MsgModbusCmdCrcErr):
     m = MemoryStream(b'')
     c = m.createClientStream(MsgModbusCmdCrcErr)
 
-    m.forward_modbus_resp = False
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['AT_Command'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
@@ -1386,13 +1381,11 @@ def test_msg_modbus_req2(ConfigTsunInv1, MsgModbusCmdCrcErr):
     assert m.db.stat['proxy']['AT_Command'] == 0
     assert m.db.stat['proxy']['Modbus_Command'] == 0
     assert m.db.stat['proxy']['Invalid_Msg_Format'] == 1
-    assert m.forward_modbus_resp == True
     m.close()
 
 def test_msg_unknown_cmd_req(ConfigTsunInv1, MsgUnknownCmd):
     ConfigTsunInv1
     m = MemoryStream(MsgUnknownCmd, (0,), False)
-    m.forward_modbus_resp = False
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['AT_Command'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
@@ -1410,15 +1403,14 @@ def test_msg_unknown_cmd_req(ConfigTsunInv1, MsgUnknownCmd):
     assert m.db.stat['proxy']['AT_Command'] == 0
     assert m.db.stat['proxy']['Modbus_Command'] == 0
     assert m.db.stat['proxy']['Invalid_Msg_Format'] == 0
-    assert m.forward_modbus_resp == False
     m.close()
 
 def test_msg_modbus_rsp1(ConfigTsunInv1, MsgModbusRsp):
+    '''Modbus response without a valid Modbus request must be dropped'''
     ConfigTsunInv1
     m = MemoryStream(MsgModbusRsp)
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = False
     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
@@ -1433,30 +1425,12 @@ def test_msg_modbus_rsp1(ConfigTsunInv1, MsgModbusRsp):
     m.close()
 
 def test_msg_modbus_rsp2(ConfigTsunInv1, MsgModbusRsp):
-    ConfigTsunInv1
-    m = MemoryStream(MsgModbusRsp)
-    m.db.stat['proxy']['Unknown_Ctrl'] = 0
-    m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = True
-    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.control == 0x1510
-    assert str(m.seq) == '03:03'
-    assert m.header_len==11
-    assert m.data_len==59
-    assert m._forward_buffer==MsgModbusRsp
-    assert m._send_buffer==b''
-    assert m.db.stat['proxy']['Unknown_Ctrl'] == 0
-    assert m.db.stat['proxy']['Modbus_Command'] == 0
-    m.close()
-
-def test_msg_modbus_rsp3(ConfigTsunInv1, MsgModbusRsp):
+    '''Modbus response with a valid Modbus request must be forwarded'''
     ConfigTsunInv1
     m = MemoryStream(MsgModbusRsp)
     m.append_msg(MsgModbusRsp)
 
-    m.forward_modbus_resp = True
+    m.mb.rsp_handler = m._SolarmanV5__forward_msg
     m.mb.last_addr = 1
     m.mb.last_fcode = 3
     m.mb.last_len = 20
@@ -1494,7 +1468,6 @@ def test_msg_unknown_rsp(ConfigTsunInv1, MsgUnknownCmdRsp):
     m = MemoryStream(MsgUnknownCmdRsp)
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = True
     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
@@ -1528,7 +1501,7 @@ def test_msg_modbus_fragment(ConfigTsunInv1, MsgModbusRsp):
     m = MemoryStream(MsgModbusRsp+b'\x00\x00\x00\x45\x10\x52\x31', (0,))
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = True
+    m.mb.rsp_handler = m._SolarmanV5__forward_msg
     m.mb.last_addr = 1
     m.mb.last_fcode = 3
     m.mb.last_len = 20
diff --git a/app/tests/test_talent.py b/app/tests/test_talent.py
index 01149f9..1f53c8c 100644
--- a/app/tests/test_talent.py
+++ b/app/tests/test_talent.py
@@ -860,11 +860,11 @@ def test_msg_modbus_req2(ConfigTsunInv1, MsgModbusCmdCrcErr):
     m.close()
 
 def test_msg_modbus_rsp1(ConfigTsunInv1, MsgModbusRsp):
+    '''Modbus response without a valid Modbus request must be dropped'''
     ConfigTsunInv1
     m = MemoryStream(MsgModbusRsp)
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = False
     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
@@ -880,33 +880,13 @@ def test_msg_modbus_rsp1(ConfigTsunInv1, MsgModbusRsp):
     assert m.db.stat['proxy']['Modbus_Command'] == 0
     m.close()
 
-def test_msg_modbus_rsp2(ConfigTsunInv1, MsgModbusRsp):
-    ConfigTsunInv1
-    m = MemoryStream(MsgModbusRsp)
-    m.db.stat['proxy']['Unknown_Ctrl'] = 0
-    m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = True
-    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.id_str == b"R170000000000001" 
-    assert m.unique_id == 'R170000000000001'
-    assert int(m.ctrl)==145
-    assert m.msg_id==119
-    assert m.header_len==23
-    assert m.data_len==13
-    assert m._forward_buffer==MsgModbusRsp
-    assert m._send_buffer==b''
-    assert m.db.stat['proxy']['Unknown_Ctrl'] == 0
-    assert m.db.stat['proxy']['Modbus_Command'] == 0
-    m.close()
-
-def test_msg_modbus_rsp3(ConfigTsunInv1, MsgModbusResp20):
+def test_msg_modbus_rsp2(ConfigTsunInv1, MsgModbusResp20):
+    '''Modbus response with a valid Modbus request must be forwarded'''
     ConfigTsunInv1
     m = MemoryStream(MsgModbusResp20)
     m.append_msg(MsgModbusResp20)
 
-    m.forward_modbus_resp = True
+    m.mb.rsp_handler = m.msg_forward
     m.mb.last_addr = 1
     m.mb.last_fcode = 3
     m.mb.last_len = 20
@@ -966,7 +946,7 @@ def test_msg_modbus_fragment(ConfigTsunInv1, MsgModbusResp20):
     m = MemoryStream(MsgModbusResp20+b'\x00\x00\x00\x45\x10\x52\x31', (0,))
     m.db.stat['proxy']['Unknown_Ctrl'] = 0
     m.db.stat['proxy']['Modbus_Command'] = 0
-    m.forward_modbus_resp = True
+    m.mb.rsp_handler = m.msg_forward
     m.mb.last_addr = 1
     m.mb.last_fcode = 3
     m.mb.last_len = 20