CINF · robertjensen · Jun 24, 2023 · Apr 10, 2026
diff --git a/PyExpLabSys/drivers/sumitomo_f70.py b/PyExpLabSys/drivers/sumitomo_f70.py
@@ -0,0 +1,145 @@
+import serial
+
+from icecream import ic
+
+
+class SumitomoF70(object):
+    def __init__(self, port='/dev/ttyUSB0'):
+        # Default comm parameters are correct, we could choose to set them though
+        self.serial = serial.Serial(port)
+        print(self.serial)
+        self.serial.timeout = 0.2
+
+    @staticmethod
+    def _crc(command):
+        # Adapted from https://github.com/Kalebu/crc16-modbus-in-Python
+        xor_value = 0xA001
+        crc = 0xFFFF
+        for byte in command:
+            crc = crc ^ ord(byte)
+            for _ in range(8):
+                if (crc & 1):  # LSB is 1
+                    crc = crc >> 1
+                    crc = crc ^ xor_value
+                else:
+                    crc = crc >> 1
+
+        return_val = hex(crc)[2:].upper()
+        return return_val
+
+    def _read_from_device(self, command, debug=False):
+        comm = command + self._crc(command) + '\r'
+        comm = comm.encode('ascii')
+        self.serial.write(comm)
+        reply = ''
+        next_char = reply = self.serial.read(1)
+        while len(next_char) > 0:
+            next_char = self.serial.read(1)
+            reply = reply + next_char
+
+        expected_crc = int(self._crc(reply[:-5].decode()), 16)
+        try:
+            actual_crc = int(reply[-5:-1].decode(), 16)
+        except ValueError:
+            print('Cannot read crc from string {}'.format(reply))
+            actual_crc = ''
+
+        # ic(expected_crc, actual_crc)
+        if expected_crc == actual_crc:
+            pre_cut = len(command) + 1  # Original command + comma
+            post_cut = -6  #  comma, 4 crc digits, CR
+            return_val = reply[pre_cut:post_cut].decode()
+        else:
+            return_val = None
+        return return_val
+
+    def _comm(self, command):
+        error = 0
+        while error > -1 and error < 10:
+            return_val = self._read_from_device(command)
+            if return_val is None:
+                error = error + 1
+                if error > 2:
+                    ic('Error is {}'.format(error))
+            else:
+                error = -1
+        return return_val
+
+    def read_firmware_and_run_hours(self):
+        command = '$ID1'
+        reply_raw = self._comm(command)
+        print(reply_raw)
+        return reply_raw
+
+    def read_temperature(self):
+        command = '$TEA'
+        reply_raw = self._comm(command)
+        temperatures_raw = reply_raw.split(',')
+        temperatures = {
+            'discharge_temp': float(temperatures_raw[0]),
+            'water_outlet_temp': float(temperatures_raw[1]),
+            'water_inlet_temp': float(temperatures_raw[2]),
+        }
+        return temperatures
+
+    def read_pressure(self):
+        command = '$PRA'
+        reply_raw = self._comm(command)
+        # print(reply_raw)
+        pressure = float(reply_raw.split(',')[0])
+        pressure_in_bar = pressure * 0.0689476
+        return pressure_in_bar
+
+    def read_status(self):
+        command = '$STA'
+        raw_reply = self._comm(command)
+        print(raw_reply)
+        # raw_reply = '0301'
+        msb = int(raw_reply[0:2], 16)
+        lsb = int(raw_reply[2:4], 16)
+
+        system_on =           bool(lsb & 0b00000001)
+        motor_alam =          bool(lsb & 0b00000010)
+        phase_sequence_alam = bool(lsb & 0b00000100)
+        helium_temp_alam =    bool(lsb & 0b00001000)
+        water_temp_alam =     bool(lsb & 0b00010000)
+        water_flow_alam =     bool(lsb & 0b00100000)
+        oil_level_alam =      bool(lsb & 0b01000000)
+        pressure_alam =       bool(lsb & 0b10000000)
+        solenoid_on =         bool(msb & 0b00000001)
+
+        state_lsb =           msb & 0b00000010
+        state_center =        msb & 0b00000100
+        state_msb =           msb & 0b00001000
+        state = 0b111 & (msb >> 1)
+
+        configureation_bit =  msb & 0b10000000
+
+        print(state_lsb, state_center, state_msb)
+        # Known value: Off is 000
+
+        status = {
+            'system_on': system_on,
+        }
+        return status
+
+
+if __name__ == '__main__':
+    F70 = SumitomoF70('/dev/ttyUSB1')
+
+    # Command to turn on compressor - not currently
+    # implemented in main driver
+    # cmd = b'$ON177CF\r'
+    # F70.serial.write(cmd)
+
+    print('temperature')
+    print(F70.read_temperature())
+    print()
+    print('pressure')
+    print(F70.read_pressure())
+    print()
+    print('status')
+    print(F70.read_status())
+
+    print('Firmware and run hours')
+    print(F70.read_firmware_and_run_hours())