--- a/gpib.py Mon Dec 17 18:57:18 2007 +0100
+++ b/gpib.py Mon Dec 17 18:58:00 2007 +0100
@@ -9,143 +9,56 @@
class ConnectionError(Exception):
pass
-GPIB_CONTROLLER = 1
-GPIB_DEVICE = 0
-
-# IEEE 488.2 Status Byte constants
-MAV = 0x10 # Message AVailable: bit 4 of the Status Byte
-ESB = 0x20 # Event Status Bit: bit 5 of the Status Byte
-MSS = 0x40 # Master Summary Status bit: bit 6 of the Status Byte (NOT
- # sent in response to a serial poll)
-RQS = 0x40 # Request Service: bit 6 of the Status Byte (when sent in
- # response to a serial poll)
-
-# SESR constants (Standard Event Status Register)
-PON = 0x80 # Power On: Power has been turned On since last register
- # read access
-URQ = 0x40 # User Request: the user has activated some device control
- # (whatever the Remote Local state is)
-CME = 0x20 # Command Error
-EXE = 0x10 # Execution Error
-DDE = 0x08 # Device Dependant Error
-QYE = 0x04 # QuerY Error (attempt to read data while Output Queue is
- # empty, or data in the OQ was lost)
-RQC = 0x02 # Request Control: tell the CiC that the device wants to
- # become the CiC
-OPC = 0x01 # Operation Complete: device has completed any pending
- # operation (ready to accept new commands). This bit is
- # generated in response to a OPC command.
+class Constants(object):
+ def __init__(self):
+ self.constants = {}
+ self.descriptions = {}
+ self.rev_constants = {}
+ for v, k, m in self._constants:
+ self.k = v
+ self.constants[v] = k
+ self.rev_constants[k] = v
+ self.descriptions[v] = m
+
+ def __getitem__(self, k):
+ if isinstance(k, basestring):
+ return self.rev_constants[k]
+ else:
+ return self.constants[k]
-#####################
-# HP3562A constants
-
-# GPIB buffer size is 3x80 characters lines
-
-# HP3562A Status Byte
-RQS = 0x40 # Request Service: when sent in response to a serial poll
-ERR = 0x20 # ERRor: GPIB error
-RDY = 0x10 #ReaDY: ready to accept GPIB commands
-
-
-class GPIB(object):
- _retries = 15
- def __init__(self, device="/dev/ttyUSB0", baudrate=115200, timeout=0.1,
- address=0, mode=1):
- """
- Create a new GPIB controller for the Prologix USB-GPIB device
- located on serial device 'device'.
- """
- self._cnx = serial.Serial(port=device, baudrate=baudrate, timeout=timeout)
- self._timeout = timeout
-
- self.set_mode(mode)
- self.set_address(address)
-
- def set_address(self, address):
- """
- Set the address of the GPIB device:
-
- - if the device is the Controller In Charge, this is the
- address of the device commands are sent to,
+ def get_description(self, k):
+ if isinstance(k, basestring):
+ k = self.rev_constants[k]
+ return self.descriptions[k]
+
- - if the device is in GPIB_DEVICE mode, this is its address.
- """
- self._set_cmd('addr', address)
- self._adress = address
-
- def set_mode(self, mode):
- """
- Set GPIB device mode to 'mode':
-
- - GPIB_CONTROLLER: set the device as the Controller In Charge
- on the GPIB bus
-
- - GPIB_DEVICE: set the device as a standard GPIB device on the
- bus.
- """
- self._set_cmd('mode', mode)
- self._mode = mode
-
- def set_controler(self):
- """
- Set GPIB device the Controller In Charge on the GPIB bus.
- """
- self.set_mode(1)
-
- def set_device(self):
- """
- Set the GPIB device as a simple device on the GPIB bus.
- """
- self.set_mode(0)
-
- def send_command(self, cmd):
- """
- Send the specified GPIB command on the bus (must be the CIC),
- and read the answer.
- """
- assert self._mode == 1
- self._cnx.write(cmd+'\r')
- time.sleep(self._timeout) # required?
- ret = self._cnx.readlines()
- return ''.join(ret)
-
- def check_srq(self):
- """
- Check the SRQ line
- """
- assert self._mode == 1, "must be the Controller In Charge"
- self._cnx.write('++srq\r')
- ret = self._cnx.readline().strip()
- if ret:
- return bool(int(ret))
- return None
-
- def poll(self):
- """
- Poll every address, and return a dictionnary
- {add: status, ...}
- """
- assert self._mode == 1, "must be the Controller In Charge"
- dico = {}
- for add in range(31):
- self._cnx.write('++spoll %d\r'%i)
- ret = self._cnx.readline().strip()
- if ret:
- dico[i] = int(ret)
- return dico
+class MODE(Constants):
+ _constants = [(1, "CONTROLLER", "Set device as Controller in Charge"),
+ (0, "DEVICE", "Set device as simple listener"),
+ ]
+# TODO
+# class STATUS_BYTE(Constants):
+# # IEEE 488.2 Status Byte constants
+# MAV = 0x10 # Message AVailable: bit 4 of the Status Byte
+# ESB = 0x20 # Event Status Bit: bit 5 of the Status Byte
+# MSS = 0x40 # Master Summary Status bit: bit 6 of the Status Byte (NOT
+# # sent in response to a serial poll)
+# RQS = 0x40 # Request Service: bit 6 of the Status Byte (when sent in
+# # response to a serial poll)
+# class SESR(Constants):
+# # SESR constants (Standard Event Status Register)
+# PON = 0x80 # Power On: Power has been turned On since last register
+# # read access
+# URQ = 0x40 # User Request: the user has activated some device control
+# # (whatever the Remote Local state is)
+# CME = 0x20 # Command Error
+# EXE = 0x10 # Execution Error
+# DDE = 0x08 # Device Dependant Error
+# QYE = 0x04 # QuerY Error (attempt to read data while Output Queue is
+# # empty, or data in the OQ was lost)
+# RQC = 0x02 # Request Control: tell the CiC that the device wants to
+# # become the CiC
+# OPC = 0x01 # Operation Complete: device has completed any pending
+# # operation (ready to accept new commands). This bit is
+# # generated in response to a OPC command.
- def _read(self):
- for i in range(self._retries):
- rdata = self._cnx.readline()
- if rdata.strip() != "":
- break
- time.sleep(self._timeout)
- return rdata
-
- def _set_cmd(self, cmd, value):
- self._cnx.write('++%s %d\r'%(cmd, value))
- self._cnx.write('++%s\r'%(cmd))
- rval = self._read().strip()
- if not rval.isdigit() or int(rval) != value:
- raise ConnectionError("Can't set GPIB %s to %s [ret=%s]"%(cmd, value, repr(rval)))
- 