Handle disabled gagues in Pfeiffer agent (#145)

* Set pressure value to zero if the channel was off. Prior to this, it threw an error when querying pressure values when channels are off

* Changes to the pfeiffer agent, trying to save some work and then update SOCS/OCS

* Adding caching method to pfieffer class

* Make os import consistent with other agents

* Fix sphinx builds by removing global logger

The problem line was `LOG = txaio.make_logger()`, though I'm not sure why, that
same usage is in plenty of other agents.

* Check strictly for gauges that are offline

This counts gauges that cannot be switched on/off as 'on', where it was
previously counting them as 'off'.

* Move disabled channel log message to debug logs

* Clean up docstring for channel_power method

* Remove check_channel_stage_changes method

* Remove call to channel_power method during acquisition

---------

Co-authored-by: Brian Koopman <[email protected]>

socs/agents/pfeiffer_tpg366/agent.py

@@ -3,12 +3,18 @@
 # Zhilei Xu, Tanay Bhandarkar
 
 import argparse
+import os
 import socket
 import time
 
+import numpy as np
+import txaio
 from ocs import ocs_agent, site_config
 from ocs.ocs_twisted import TimeoutLock
 
+# For logging
+txaio.use_twisted()
+
 BUFF_SIZE = 128
 ENQ = '\x05'
 
@@ -29,12 +35,36 @@ class Pfeiffer:
     """
 
     def __init__(self, ip_address, port, timeout=10,
-                 f_sample=2.5):
+                 f_sample=1.):
         self.ip_address = ip_address
         self.port = port
         self.comm = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.comm.connect((self.ip_address, self.port))
         self.comm.settimeout(timeout)
+        self.log = txaio.make_logger()
+
+    def channel_power(self):
+        """
+        Function to check the power status of all channels.
+
+        Args:
+            None
+
+        Returns:
+            List of channel states.
+
+        """
+        msg = 'SEN\r\n'
+        self.comm.send(msg.encode())
+        self.comm.recv(BUFF_SIZE).decode()
+        self.comm.send(ENQ.encode())
+        read_str = self.comm.recv(BUFF_SIZE).decode()
+        power_str = read_str.split('\r')
+        power_states = np.array(power_str[0].split(','), dtype=int)
+        if any(chan == 1 for chan in power_states):
+            channel_states = [index + 1 for index, state in enumerate(power_states) if state == 1]
+            self.log.debug("The following channels are off: {}".format(channel_states))
+        return channel_states
 
     def read_pressure(self, ch_no):
         """
@@ -50,7 +80,6 @@ def read_pressure(self, ch_no):
         """
         msg = 'PR%d\r\n' % ch_no
         self.comm.send(msg.encode())
-        # Can use this to catch exemptions, for troubleshooting
         self.comm.recv(BUFF_SIZE).decode()
         self.comm.send(ENQ.encode())
         read_str = self.comm.recv(BUFF_SIZE).decode()
@@ -76,9 +105,14 @@ def read_pressure_all(self):
         self.comm.send(ENQ.encode())
         read_str = self.comm.recv(BUFF_SIZE).decode()
         pressure_str = read_str.split('\r')[0]
-        # gauge_states = pressure_str.split(',')[::2]
+        gauge_states = pressure_str.split(',')[::2]
+        gauge_states = np.array(gauge_states, dtype=int)
         pressures = pressure_str.split(',')[1::2]
         pressures = [float(p) for p in pressures]
+        if any(state != 0 for state in gauge_states):
+            index = np.where(gauge_states != 0)
+            for j in index[0]:
+                pressures[j] = 0.
         return pressures
 
     def close(self):
@@ -88,7 +122,7 @@ def close(self):
 
 class PfeifferAgent:
 
-    def __init__(self, agent, ip_address, port, f_sample=2.5):
+    def __init__(self, agent, ip_address, port, f_sample=1.):
         self.active = True
         self.agent = agent
         self.log = agent.log
@@ -97,7 +131,6 @@ def __init__(self, agent, ip_address, port, f_sample=2.5):
         self.take_data = False
         self.gauge = Pfeiffer(ip_address, int(port))
         agg_params = {'frame_length': 60, }
-
         self.agent.register_feed('pressures',
                                  record=True,
                                  agg_params=agg_params,
@@ -130,13 +163,15 @@ def acq(self, session, params=None):
                 return False, "Could not acquire lock."
 
             self.take_data = True
-
             while self.take_data:
                 data = {
                     'timestamp': time.time(),
                     'block_name': 'pressures',
                     'data': {}
                 }
+                # Useful for debugging, but should separate to a task to cut
+                # down on queries in the main acq() loop.
+                # self.gauge.channel_power()
                 pressure_array = self.gauge.read_pressure_all()
                 # Loop through all the channels on the device
                 for channel in range(len(pressure_array)):
@@ -180,6 +215,9 @@ def make_parser(parser=None):
 
 
 def main(args=None):
+    # Start logging
+    txaio.start_logging(level=os.environ.get("LOGLEVEL", "info"))
+
     parser = make_parser()
     args = site_config.parse_args(agent_class='PfeifferAgent',
                                   parser=parser,