diff --git a/platform/panduza_platform/connectors/serial_tty.py b/platform/panduza_platform/connectors/serial_tty.py
index 1ad5660..ceadd36 100644
--- a/platform/panduza_platform/connectors/serial_tty.py
+++ b/platform/panduza_platform/connectors/serial_tty.py
@@ -15,6 +15,9 @@ class SerialTty(SerialBase):
     # Hold instances mutex
     __MUTEX = asyncio.Lock()
 
+    # Hold instances mutex
+    __MUTEX = asyncio.Lock()
+
     # Contains instances
     __INSTANCES = {}
 
@@ -90,6 +93,10 @@ def __init__(self, loop,**kwargs):
         # Init local mutex
         self._mutex = asyncio.Lock()
 
+        # Init command mutex
+        self._cmd_mutex = asyncio.Lock()
+
+
         # Init time lock
         self._time_lock_s = None
         
@@ -125,6 +132,14 @@ async def connect(self):
     # =============================================================================
     # OVERRIDE FROM SERIAL_BASE
 
+
+    async def beg_cmd(self):
+        await self._cmd_mutex.acquire()
+
+    async def end_cmd(self):
+        self._cmd_mutex.release()
+
+
     # ---
 
     async def read_data(self, n_bytes = None):
diff --git a/platform/panduza_platform/drivers/ammeter/drv_korad_ka3005p_ammeter.py b/platform/panduza_platform/drivers/ammeter/drv_korad_ka3005p_ammeter.py
index 02c7f4d..1585e96 100644
--- a/platform/panduza_platform/drivers/ammeter/drv_korad_ka3005p_ammeter.py
+++ b/platform/panduza_platform/drivers/ammeter/drv_korad_ka3005p_ammeter.py
@@ -39,9 +39,11 @@ async def _PZA_DRV_loop_init(self, loop, tree):
     # ---
 
     async def _PZA_DRV_AMMETER_read_measure_value(self):
+        await self.serial_connector.beg_cmd()
         cmd = "IOUT1?"
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
         current = await self.serial_connector.read_data(n_bytes=5)
+        await self.serial_connector.end_cmd()
         return float(current)
 
     # ---
\ No newline at end of file
diff --git a/platform/panduza_platform/drivers/bpc/drv_korad_ka3005p_bpc.py b/platform/panduza_platform/drivers/bpc/drv_korad_ka3005p_bpc.py
index cdf391f..db94cba 100644
--- a/platform/panduza_platform/drivers/bpc/drv_korad_ka3005p_bpc.py
+++ b/platform/panduza_platform/drivers/bpc/drv_korad_ka3005p_bpc.py
@@ -53,35 +53,39 @@ async def _PZA_DRV_loop_init(self, loop, tree):
     ###########################################################################
 
     async def _PZA_DRV_BPC_read_enable_value(self):
-        await asyncio.sleep(1)
+        # await asyncio.sleep(1)
         print("Sending cmd: {}".format("STATUS?"))
+        await self.serial_connector.beg_cmd()
         await self.serial_connector.write_data("STATUS?", time_lock_s=COMMAND_TIME_LOCK)
         status = await self.serial_connector.read_data(n_bytes=1)
         print("LOL", status)
+        await self.serial_connector.end_cmd()
         return bool(status[0] & (1 << 6))
 
     async def _PZA_DRV_BPC_write_enable_value(self, v):
-        await asyncio.sleep(1)
+        await self.serial_connector.beg_cmd()
         cmd = "OUT{}".format(int(v))
         print("Sending cmd: {}".format(cmd))
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
         status = await self.serial_connector.read_data(n_bytes=1)
-        await asyncio.sleep(1)
+        await self.serial_connector.end_cmd()
 
     # ---
 
     async def _PZA_DRV_BPC_read_voltage_value(self):
-        await asyncio.sleep(0.2)
+        await self.serial_connector.beg_cmd()
         cmd = "VSET1?"
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
         voltage = await self.serial_connector.read_data(n_bytes=5)
         return float(voltage)
+        await self.serial_connector.end_cmd()
 
     async def _PZA_DRV_BPC_write_voltage_value(self, v):
-        await asyncio.sleep(0.2)
+        await self.serial_connector.beg_cmd()
         v = "{:05.2f}".format(v)
         cmd = "VSET1:{}".format(v)
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
+        await self.serial_connector.end_cmd()
 
     async def _PZA_DRV_BPC_voltage_value_min_max(self):
         return VOLTAGE_BOUNDS
@@ -92,18 +96,20 @@ async def _PZA_DRV_BPC_read_voltage_decimals(self):
     # ---
 
     async def _PZA_DRV_BPC_read_current_value(self):
-        await asyncio.sleep(0.2)
+        await self.serial_connector.beg_cmd()
         cmd = "ISET1?"
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
         current = await self.serial_connector.read_data(n_bytes=5)
+        await self.serial_connector.end_cmd()
         return float(current)
 
     async def _PZA_DRV_BPC_write_current_value(self, v):
-        await asyncio.sleep(0.2)
+        await self.serial_connector.beg_cmd()
         v = "{:05.3f}".format(v)
         cmd = "ISET1:{}".format(v)
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
-
+        await self.serial_connector.end_cmd()
+        
     async def _PZA_DRV_BPC_current_value_min_max(self):
         return CURRENT_BOUNDS
 
diff --git a/platform/panduza_platform/drivers/bpc/drv_tenma_722710_bpc.py b/platform/panduza_platform/drivers/bpc/drv_tenma_722710_bpc.py
index b08d7f2..857d689 100644
--- a/platform/panduza_platform/drivers/bpc/drv_tenma_722710_bpc.py
+++ b/platform/panduza_platform/drivers/bpc/drv_tenma_722710_bpc.py
@@ -67,10 +67,11 @@ async def _PZA_DRV_loop_init(self, loop, tree):
     async def _PZA_DRV_BPC_read_enable_value(self):
         # Send "STATUS?" to get back the output state
 
-        
+        await self.serial_connector.beg_cmd()
         await self.serial_connector.write_data(f"STATUS?\n", time_lock_s=COMMAND_TIME_LOCK)
         statusBytes = await self.serial_connector.read_data()
-        
+        await self.serial_connector.end_cmd()
+
         self.log.debug(f"{statusBytes.strip()}")
         status = ord(statusBytes.strip())
 
diff --git a/platform/panduza_platform/drivers/voltmeter/drv_korad_ka3005p_voltmeter.py b/platform/panduza_platform/drivers/voltmeter/drv_korad_ka3005p_voltmeter.py
index 247f9a2..9f8789c 100644
--- a/platform/panduza_platform/drivers/voltmeter/drv_korad_ka3005p_voltmeter.py
+++ b/platform/panduza_platform/drivers/voltmeter/drv_korad_ka3005p_voltmeter.py
@@ -40,8 +40,11 @@ async def _PZA_DRV_loop_init(self, loop, tree):
 
     async def _PZA_DRV_VOLTMETER_read_measure_value(self):
         cmd = "VOUT1?"
+        await self.serial_connector.beg_cmd()
         await self.serial_connector.write_data(cmd, time_lock_s=COMMAND_TIME_LOCK)
         voltage = await self.serial_connector.read_data(n_bytes=5)
+        await self.serial_connector.end_cmd()
+
         return float(voltage)
 
     # ---
\ No newline at end of file