Make Bronkhorst driver able to have multiple serial ports and multiple nodes connected in series.

PyExpLabSys/drivers/bronkhorst.py

@@ -9,67 +9,94 @@
 
 class Bronkhorst(object):
     """ Driver for Bronkhorst flow controllers """
-    def __init__(self, port, max_flow):
-        self.ser = serial.Serial(port, 38400, timeout=2)
+    def __init__(self, port, max_flow, node_channel=None, serial=None):
+        #Check for default serial for back compadibility
+        if serial is None:
+            self.ser = serial.Serial(port, 38400, timeout=2)
+        else:
+            self.ser = serial
+
         self.max_setting = max_flow
-        time.sleep(0.25)
-        ser = self.read_serial()
-        if len(ser) < 3:
+
+        #Check for default node_channel for back compadibility
+        if node_channel is None:
+            self.node = 80
+        else :
+            self.node = node_channel #In hex
+
+        if len(serial) < 3:
             raise Exception('MfcNotFound')
 
+
     def comm(self, command):
         """ Send commands to device and recieve reply """
         self.ser.write(command.encode('ascii'))
         time.sleep(0.1)
+
         return_string = self.ser.read(self.ser.inWaiting())
         return_string = return_string.decode()
         return return_string
 
+
+
     def read_setpoint(self):
         """ Read the current setpoint """
-        read_setpoint = ':06800401210121\r\n' # Read setpoint
+        read_setpoint = ':06' + self.node + '0401210121\r\n' # Read setpoint
         response = self.comm(read_setpoint)
-        response = int(response[11:], 16)
-        response = (response / 32000.0) * self.max_setting
+        response = int(response[11:], 16) #Grabs last 4 hex numbers and converts to decimal
+        response = (float(response) / 32000.0) * float(self.max_setting) #response / 32000 gives percentage, then multiply by max setting
         return response
 
+
+
     def read_flow(self):
-        """ Read the actual flow """
+        """ Read the actual flow """ #If 10 errors then returns 99
         error = 0
         while error < 10:
-            read_pressure = ':06800401210120\r\n' # Read pressure
+            read_pressure = ':06' + self.node + '0401210120\r\n' # Read pressure
             val = self.comm(read_pressure)
+
             try:
-                val = val[-6:]
-                num = int(val, 16)
-                pressure = (1.0 * num / 32000) * self.max_setting
+                val = val[11:] #Gets last 4 hex digits
+                num = int(val, 16) #Converts to decimal
+                pressure = (float(num)/ 32000) * float(self.max_setting) #Determines actual flow
                 break
+
             except ValueError:
                 pressure = -99
                 error = error + 1
+
         return pressure
 
+
     def set_flow(self, setpoint):
+
         """ Set the desired setpoint, which could be a pressure """
-        setpoint = float(setpoint)
         if setpoint > 0:
-            setpoint = (1.0 * setpoint / self.max_setting) * 32000
+            setpoint = (float(setpoint) / float(self.max_setting)) * 32000
             setpoint = hex(int(setpoint))
             setpoint = setpoint.upper()
             setpoint = setpoint[2:].rstrip('L')
+
             if len(setpoint) == 3:
                 setpoint = '0' + setpoint
+
         else:
             setpoint = '0000'
-        set_setpoint = ':0680010121' + setpoint + '\r\n' # Set setpoint
+
+        set_setpoint = ':06' + self.node + '010121' + setpoint + '\r\n' # Set setpoint
         response = self.comm(set_setpoint)
         response_check = response[5:].strip()
+
         if response_check == '000005':
             response = 'ok'
         else:
             response = 'error'
+
         return response
 
+
+
     def read_counter_value(self):
         """ Read valve counter. Not fully implemented """
         read_counter = ':06030401210141\r\n'
@@ -78,13 +105,14 @@ def read_counter_value(self):
 
     def set_control_mode(self):
         """ Set the control mode to accept rs232 setpoint """
-        set_control = ':058001010412\r\n'
+        set_control = ':05' + self.node + '01010412\r\n' #Sets control mode to value 18 (rs232)
         response = self.comm(set_control)
         return str(response)
 
+
     def read_serial(self):
-        """ Read the serial number of device """
-        read_serial = ':1A8004F1EC7163006D71660001AE0120CF014DF0017F077101710A\r\n'
+        """ Read the serial number of device """        
+        read_serial = ':1A' + self.node + '04F1EC7163006D71660001AE0120CF014DF0017F077101710A\r\n'
         error = 0
         while error < 10:
             response = self.comm(read_serial)
@@ -99,39 +127,51 @@ def read_serial(self):
                     response = bytes.fromhex(response).decode('utf-8')
                 except ValueError:
                     response = ''
+
             if response == '':
                 error = error + 1
             else:
                 error = 10
+
         return str(response)
 
+
     def read_unit(self):
         """ Read the flow unit """
-        read_capacity = ':1A8004F1EC7163006D71660001AE0120CF014DF0017F077101710A\r\n'
+        read_capacity = ':1A' + self.node + '04F1EC7163006D71660001AE0120CF014DF0017F077101710A\r\n'
         response = self.comm(read_capacity)
         response = response[77:-26]
+
         try:
             response = bytes.fromhex(response).decode('utf-8')
         except AttributeError: # Python2
             response = response.decode('hex')
 
         return str(response)
 
+
     def read_capacity(self):
-        """ Read ?? from device """
-        read_capacity = ':1A8004F1EC7163006D71660001AE0120CF014DF0017F077101710A\r\n'
+        """ Read ?? from device (Not implemented)"""
+        read_capacity = ':1A' + self.node + '04F1EC7163006D71660001AE0120CF014DF0017F077101710A\r\n'
         response = self.comm(read_capacity)
         response = response[65:-44]
         #response = response.decode('hex')
         return str(response)
 
 
 if __name__ == '__main__':
-    bh = Bronkhorst('/dev/ttyUSB3', 5)
+    ser1 = serial.Serial('/dev/ttyUSB3', 38400, timeout=2)
+    ser2 = serial.Serial('/dev/COM3', 38400, timeout=2)
+    bh_arr = []
+    bh_arr.append(Bronkhorst(None, 100, hex(10), ser1))
+    bh_arr.append(Bronkhorst(None, 100, hex(20), ser1))
+    bh_arr.append(Bronkhorst(None, 100, hex(30), ser1))
+    bh_arr.append(Bronkhorst(None, 100, hex(40), ser2))
     #print bh.set_setpoint(1.0)
     #time.sleep(1)
-    print(bh.read_serial())
-    print(bh.read_flow())
-    print(bh.read_unit())
-    print(bh.read_capacity())
-    print(bh.read_counter_value())
+    for bh in bh_arr:
+        print(bh.read_serial())
+        print(bh.read_flow())
+        print(bh.read_unit())
+        print(bh.read_capacity())
+        print(bh.read_counter_value())