Pfeiffer Endpoint: Implementation of Pfeiffer telegram protocol

Dockerfile

@@ -1,7 +1,6 @@
 ARG img_user=ghcr.io/driplineorg
 ARG img_repo=dripline-python
-#ARG img_tag=develop-dev
-ARG img_tag=v5.1.0
+ARG img_tag=v5.1.2
 
 FROM ${img_user}/${img_repo}:${img_tag}
 

dripline/extensions/__init__.py

@@ -12,3 +12,4 @@
 from .asteval_endpoint import *
 from .thermo_fisher_endpoint import *
 from .ethernet_thermo_fisher_service import *
+from .pfeiffer_endpoint import *

dripline/extensions/pfeiffer_endpoint.py

@@ -0,0 +1,153 @@
+from dripline.core import Entity, calibrate, ThrowReply
+
+import logging
+logger = logging.getLogger(__name__)
+
+__all__ = []
+
+__all__.append('PfeifferEntity')
+class PfeifferEntity(Entity):
+    '''
+    Pfeiffer Entity implements the Telegram protocol by Pfeiffer. 
+    The message contains commands in form of parameter numbers and different length data that depend on the given datatype.
+    Conversion of datatypes and checksum checking are implemented.
+    '''
+
+    _datatype = {"bool_old": 6, 
+                 "uint":     6, 
+                 "ureal":    6, 
+                 "string":   6, 
+                 "bool":     1, 
+                 "ushort":   3, 
+                 "uexpo":    6, 
+                 "str16":   16, 
+                 "str8":     8, 
+                 "query":    2
+                 }
+
+    def __init__(self,
+                 parameter = 303,
+                 datatype = "uexpo",
+                 unit_address = 1,
+                 **kwargs):
+        '''
+        Args:
+            parameter (int): number of the parameter as documented in the manual"
+            datatype (str): one of ["bool_old", "uint", "ureal", "string", "bool", "ushort", "uexpo", "str16", "str8"
+            unit_address (int): number of the unit address, allwoed range: 1-16
+        '''
+        Entity.__init__(self, **kwargs)
+        self.parameter = parameter
+        self.datatype = datatype
+        self.unit_address = unit_address
+
+    def get_checksum(self, string):
+        return sum([ord(c) for c in string])%256
+
+    def format_value(self, value):
+        if self.datatype == "bool_old":
+            return "111111" if value else "000000"
+        if self.datatype == "bool":
+            return "1" if value else "0"
+        if self.datatype == "string":
+            return f"{value:6s}"
+        if self.datatype == "str8":
+            return f"{value:8s}"
+        if self.datatype == "str16":
+            return f"{value:16s}"
+        if self.datatype == "uint":
+            return f"{value:06d}"
+        if self.datatype == "ushort":
+            return f"{value:03d}"
+        if self.datatype == "ureal":
+            val = int(value*100)
+            return f"{val:06d}"
+        if self.datatype == "uexpo":
+            expon = int(np.log10(val)//1)
+            val = int(val/10**expon*1000)
+            expon_mod = expon - 20
+            return f"{val:04d}{expon_mod:02d}"
+        return value
+
+    def unformat_value(self, value):
+        if value in ["NO_DEF", "_RANGE", "_LOGIC"]:
+            raise ValueError(f"Device responded with an error {value}")
+        if len(value) != self._datatype[self.datatype]:
+            raise ValueError(f"data does not match length of datatype")
+
+        if self.datatype ==  "bool_old":
+            return value == "111111"
+        if self.datatype == "bool":
+            return value == 1 
+        if self.datatype in ["string", "str16", "str8"]:
+            return value
+        if self.datatype in ["uint", "ushort"]:
+            return int(value)
+        if self.datatype == "ureal":
+            return int(value)/100.
+        if self.datatype == "uexpo":
+            return int(value[:4])/1000. * 10**(int(value[4:]) - 20)
+        return value
+
+    def disensemble_result(self, reply):
+        if self.get_checksum(reply[:-3]) != int(reply[-3:]):
+            logger.warning("checksum not matching")
+        # split message into its constituents, we do not need all of them
+        # address = int(reply[:3])
+        # action = reply[3:5]
+        # parameter = int(reply[5:8])
+        length = int(reply[8:10])
+        data = reply[10:10+length]
+        return data
+
+    @calibrate()
+    def on_get(self):
+        value = "=?"
+        cmd = f"{self.unit_address:03d}00{self.parameter:03d}{len(value):02d}{value}"
+        cs = self.get_checksum(cmd) 
+        cmd += f"{cs:03d}"
+        result = self.service.send_to_device([cmd])
+        logger.debug(f'raw result is: {result}')
+        result = self.disensemble_result(result)
+        logger.debug(f'disensembled result is: {result}')
+        result = self.unformat_value(result)
+        logger.debug(f'unformated result is: {result}')
+        return result
+
+    def on_set(self, value):
+        value = self.format_value(value)
+        cmd = f"{self.unit_address:03d}10{self.parameter:03d}{len(value):02d}{value}"
+        cs = self.get_checksum(cmd) 
+        cmd += f"{cs:03d}"
+        result = self.service.send_to_device([cmd])
+        logger.debug(f'raw result is: {result}')
+        result = self.disensemble_result(result)
+        logger.debug(f'disensembled result is: {result}')
+        result = self.unformat_value(result)
+        logger.debug(f'unformated result is: {result}')
+        return result 
+
+__all__.append('PfeifferGetEntity')
+class PfeifferGetEntity(PfeifferEntity):
+    '''
+    Identical to PfeifferEntity, but with an explicit exception if on_set is attempted
+    '''
+
+    def __init__(self, **kwargs):
+        PfeifferEntity.__init__(self, **kwargs)
+
+    def on_set(self, value):
+        raise ThrowReply('message_error_invalid_method', f"endpoint '{self.name}' does not support set")
+
+
+__all__.append('PfeifferSetEntity')
+class PfeifferSetEntity(PfeifferEntity):
+    '''
+    Modelled on PfeifferEntity, but with an explicit exception if on_get is attempted.
+    '''
+
+    def __init__(self, **kwargs):
+        PfeifferEntity.__init__(self, **kwargs)
+
+    def on_get(self):
+        raise ThrowReply('message_error_invalid_method', f"endpoint '{self.name}' does not support get")

examples/pressure_gauge_60.yaml

@@ -0,0 +1,28 @@
+runtime-config:
+  name: pressure_gauge_60
+  module: EthernetSCPIService
+  #module: EthernetPfeifferService
+  socket_timeout: 5
+  socket_info: ("10.93.130.113", 10001) # astro-pirate
+  cmd_at_reconnect:
+      - "0010034902=?111" # Check for model name
+  reconnect_test: "0011034906HPT200118"
+  command_terminator: "\r"      # is what goes after the command sent
+  response_terminator: "\r"      # is what goes after the command sent
+  endpoints:
+    - name: pg60_error_status
+      module: PfeifferGetEntity
+      parameter: 303
+      datatype: string
+      log_interval: 10
+
+    - name: pg60_pressure_mbar
+      module: PfeifferEntity
+      parameter: 740
+      datatype: uexpo
+      log_interval: 10
+
+    - name : pg60_goal_degas     
+      module:  PfeifferEntity
+      parameter: 40
+      datatype: bool