diff --git a/frappy_psi/pfeiffer_new.py b/frappy_psi/pfeiffer_new.py
index 2a9e805..b1e1785 100644
--- a/frappy_psi/pfeiffer_new.py
+++ b/frappy_psi/pfeiffer_new.py
@@ -12,25 +12,29 @@ from frappy.errors import CommunicationFailedError
 class PfeifferProtocol(StringIO): 
     end_of_line = '\r'
 
+    @staticmethod
+    def calculate_crc(data):
+        crc = sum(ord(ch) for ch in data) % 256
+        return f'{crc:03d}'
+
+    @staticmethod
+    def check_crc(data):
+        if data[-3:] != PfeifferProtocol.calculate_crc(data[:-3]):
+            raise CommunicationFailedError('Bad crc')
+
+    def communicate(self, cmd):
+        cmd += self.calculate_crc(cmd) 
+        reply = super().communicate(cmd)
+        self.check_crc(reply)
+        return reply[:-3]
+
+
 class PfeifferMixin(HasIO): 
     ioClass = PfeifferProtocol    
     address= Property('Addresse', datatype= IntRange())
 
-    def calculate_crc(self, data):
-        crc = sum(ord(chr) for chr in data)  % 256
-        return f'{crc:03d}'
-
-    def check_crc(self, data):
-       if data [-3:] != self.calculate_crc(data[:-3]):
-           raise CommunicationFailedError('Bad crc')
-       
     def data_request_u_expo_new(self, parameter_nr):
-        cmd = f'{self.address:03d}00{parameter_nr:03d}02=?'
-        cmd += self.calculate_crc(cmd) 
-                
-        reply = self.communicate(cmd)
-        self.check_crc(reply)
-        
+        reply = self.communicate(f'{self.address:03d}00{parameter_nr:03d}02=?')
         
         assert int(reply[5:8]) == parameter_nr
         
@@ -40,23 +44,16 @@ class PfeifferMixin(HasIO):
             exponent = int(reply[14:16])-23
         except ValueError:
             raise CommunicationFailedError(f'got {reply[10:16]}')
-          
 
         return float(f'{reply[10:14]}e{exponent}')
         
     def data_request_old_boolean(self, parameter_nr):
-        
-        
-        cmd = f'{self.address:03d}00{parameter_nr:03d}02=?'
-        cmd += self.calculate_crc(cmd) 
-        
-        reply = self.communicate(cmd)
-        self.check_crc(reply)
+
+        reply = self.communicate(f'{self.address:03d}00{parameter_nr:03d}02=?')
         assert int(reply[5:8]) == parameter_nr, f"Parameter number mismatch: expected {parameter_nr}, got {int(reply[5:8])}"
         
         assert int(reply[0:3]) == self.address, f"Address mismatch: expected {self.address}, got {int(reply[0:3])}"
-        
-        
+
         if reply[12] == "1": 
                 value = True
         elif reply[12] == "0": 
@@ -67,12 +64,8 @@ class PfeifferMixin(HasIO):
         return value
     
     def data_request_u_real(self, parameter_nr):
-        cmd = f'{self.address:03d}00{parameter_nr:03d}02=?'
-        cmd += self.calculate_crc(cmd) 
-        
-        reply = self.communicate(cmd)
-        self.check_crc(reply)
-        
+        reply = self.communicate(f'{self.address:03d}00{parameter_nr:03d}02=?')
+
         assert int(reply[5:8]) == parameter_nr
         
         assert int(reply[0:3]) == self.address
@@ -83,19 +76,14 @@ class PfeifferMixin(HasIO):
             raise CommunicationFailedError(f'got {reply[10:16]}')
         
         return value
-    
-   
+
     def data_request_u_int(self, parameter_nr):
-        cmd = f'{self.address:03d}00{parameter_nr:03d}02=?'
-        cmd += self.calculate_crc(cmd) 
-        
-        reply = self.communicate(cmd)
-        self.check_crc(reply)
-        
+        reply = self.communicate(f'{self.address:03d}00{parameter_nr:03d}02=?')
+
         if reply[8] == "0":
-            reply_length = (int)(reply[9])
+            reply_length = int(reply[9])
         else:
-            reply_length = (int)(reply[8:10])
+            reply_length = int(reply[8:10])
                 
         try:
             if reply[10 : 10 + reply_length] == "000000": 
@@ -108,31 +96,24 @@ class PfeifferMixin(HasIO):
         return value
     
     def data_request_string(self, parameter_nr):
-        cmd = f'{self.address:03d}00{parameter_nr:03d}02=?'
-        cmd += self.calculate_crc(cmd) 
-        
-        reply = self.communicate(cmd)
-        self.check_crc(reply)
-        
+        reply = self.communicate(f'{self.address:03d}00{parameter_nr:03d}02=?')
+
         assert int(reply[5:8]) == parameter_nr
         
         assert int(reply[0:3]) == self.address
         
         return str(reply[10:16])
-        
-        
+
     def control_old_boolean(self, parameter_nr, target):
         if target: 
             val = 1
         else:
             val = 0
-            
+
         cmd = f'{self.address:03d}10{parameter_nr:03d}06{str(val)*6}'
-        cmd += self.calculate_crc(cmd) 
-        
+
         reply = self.communicate(cmd)
-        self.check_crc(reply)
-        
+
         assert cmd == reply, f'got {reply}  instead of {cmd} '
         
         try:
@@ -145,25 +126,29 @@ class PfeifferMixin(HasIO):
             raise CommunicationFailedError(f'got {reply[10:16]}')
         
         return value
-        
+
+
 class RPT200(PfeifferMixin, Readable):   
     value = Parameter('Pressure', FloatRange(unit='hPa'))
 
     def read_value(self):
         return self.data_request_u_expo_new(740)
+
     def read_status(self):
         errtxt = self.data_request_string(303)
         if errtxt == "000000":
             return IDLE, ''
         else: 
             return ERROR, errtxt
-    
+
+
 class TCP400(PfeifferMixin, Drivable, Readable):
     speed= Parameter('Rotational speed', FloatRange(unit = 'Hz'), readonly = False)
     target= Parameter('Pumping station', BoolType())
     current= Parameter('Current consumption', FloatRange(unit = '%'))
     value = Parameter('Turbopump state', BoolType())    
     temp = Parameter('temp', FloatRange(unit = 'C'))
+
     def read_temp (self):
         return self.data_request_u_int(326)
    
@@ -184,6 +169,9 @@ class TCP400(PfeifferMixin, Drivable, Readable):
         
     def read_status(self): 
         if not self.data_request_old_boolean(306):
-            return BUSY, 'ramping up'
+            if self.target:
+                return BUSY, 'ramping up'
+            else:
+                return IDLE, ''
         else: 
-            return IDLE,'at targetspeed'
+            return IDLE, 'at targetspeed'