Source code for qblox_instruments.ieee488_2.ieee488_2
# ----------------------------------------------------------------------------
# Description : IEEE488.2 interface
# Git repository : https://gitlab.com/qblox/packages/software/qblox_instruments.git
# Copyright (C) Qblox BV (2020)
# ----------------------------------------------------------------------------
# -- include -----------------------------------------------------------------
from qblox_instruments.ieee488_2 import Transport
# -- class -------------------------------------------------------------------
[docs]
class Ieee488_2:
"""
Class that implements the IEEE488.2 interface.
"""
# ------------------------------------------------------------------------
[docs]
def __init__(self, transport: Transport):
"""
Creates IEEE488.2 interface object.
Parameters
----------
transport : Transport
Transport class responsible for the lowest level of communication
(e.g. ethernet).
Returns
----------
Raises
----------
"""
self._transport = transport
# ------------------------------------------------------------------------
def _write(self, cmd_str: str) -> None:
"""
Write command to instrument
Parameters
----------
cmd_str : str
Command string.
Returns
----------
Raises
----------
"""
self._transport.write(cmd_str + " ")
# ------------------------------------------------------------------------
def _write_bin(self, cmd_str: str, bin_block: bytes) -> None:
"""
Write command and binary data block to instrument
Parameters
----------
cmd_str : str
Command string.
bin_block : bytes
Binary data array to send.
Returns
----------
Raises
----------
"""
self._bin_block_write(cmd_str + " ", bin_block)
# ------------------------------------------------------------------------
def _read(self, cmd_str: str) -> str:
"""
Write command to instrument and read response. Using an empty command
string will skip the write and only read.
Parameters
----------
cmd_str : str
Command string.
Returns
----------
str
Command response string.
Raises
----------
"""
self._transport.write(cmd_str)
return (
self._transport.readline().rstrip()
) # Remove trailing white space, CR, LF
# ------------------------------------------------------------------------
def _read_bin(self, cmd_str: str, flush_line_end: bool = True) -> bytes:
"""
Write command to instrument and read binary data block. Using an empty
command string will skip the write and only read to allow reading
concatinated binary blocks.
Parameters
----------
cmd_str : str
Command string.
flush_line_end : bool
Flush end of line characters.
Returns
----------
bytes
Binary data array received.
Raises
----------
"""
if cmd_str != "":
self._transport.write(cmd_str)
return self._bin_block_read(flush_line_end)
# ------------------------------------------------------------------------
def _bin_block_write(self, cmd_str: str, bin_block: bytes) -> None:
"""
Write IEEE488.2 binary data block to instrument.
Parameters
----------
cmd_str : str
Command string.
bin_block : bytes
Binary data array to send.
Returns
----------
Raises
----------
"""
header = cmd_str + Ieee488_2._build_header_string(len(bin_block))
bin_msg = header.encode() + bin_block
self._transport.write_binary(bin_msg)
self._transport.write("") # Add a Line Terminator
# ------------------------------------------------------------------------
def _bin_block_read(self, flush_line_end: bool = True) -> bytes:
"""
Read IEEE488.2 binary data block from instrument.
Parameters
----------
flush_line_end : bool
Flush end of line characters.
Returns
----------
bytes
Binary data array received.
Raises
----------
RunTimeError
Header error.
"""
header_a = self._transport.read_binary(2) # Read '#N'
header_a_str = header_a.decode()
if header_a_str[0] != "#":
s = f"Header error: received {header_a}"
raise RuntimeError(s)
digit_cnt = int(header_a_str[1])
header_b = self._transport.read_binary(digit_cnt)
byte_cnt = int(header_b.decode())
bin_block = self._transport.read_binary(byte_cnt)
if flush_line_end:
self._flush_line_end()
return bin_block
# ------------------------------------------------------------------------
@staticmethod
def _build_header_string(byte_cnt: int) -> str:
"""
Generate IEEE488.2 binary data block header.
Parameters
----------
byte_cnt : int
Size of the binary data block in bytes.
Returns
----------
str
Header string.
Raises
----------
"""
byte_cnt_str = str(byte_cnt)
digit_cnt_str = str(len(byte_cnt_str))
bin_header_str = "#" + digit_cnt_str + byte_cnt_str
return bin_header_str
# ------------------------------------------------------------------------
def _flush_line_end(self) -> None:
"""
Flush end of line <CR><LF> characters.
Parameters
----------
Returns
----------
Raises
----------
"""
self._transport.read_binary(2) # Consume <CR><LF>
# ------------------------------------------------------------------------
# IEEE488.2 constants
# ------------------------------------------------------------------------
# *ESR and *ESE bits
_ESR_OPERATION_COMPLETE = 0x01
_ESR_REQUEST_CONTROL = 0x02
_ESR_QUERY_ERROR = 0x04
_ESR_DEVICE_DEPENDENT_ERROR = 0x08
_ESR_EXECUTION_ERROR = 0x10
_ESR_COMMAND_ERROR = 0x20
_ESR_USER_REQUEST = 0x40
_ESR_POWER_ON = 0x80
# STATus:OPERation bits
_STAT_OPER_CALIBRATING = (
0x0001 # The instrument is currently performing a calibration
)
_STAT_OPER_SETTLING = 0x0002 # The instrument is waiting for signals it controls to stabilize enough to begin measurements
_STAT_OPER_RANGING = 0x0004 # The instrument is currently changing its range
_STAT_OPER_SWEEPING = 0x0008 # A sweep is in progress
_STAT_OPER_MEASURING = 0x0010 # The instrument is actively measuring
_STAT_OPER_WAIT_TRIG = (
0x0020 # The instrument is in a “wait for trigger” state of the trigger model
)
_STAT_OPER_WAIT_ARM = (
0x0040 # The instrument is in a “wait for arm” state of the trigger model
)
_STAT_OPER_CORRECTING = (
0x0080 # The instrument is currently performing a correction
)
_STAT_OPER_INST_SUMMARY = (
0x2000 # One of n multiple logical instruments is reporting OPERational status
)
_STAT_OPER_PROG_RUNNING = (
0x4000 # A user-defined program is currently in the run state
)
# STATus:QUEStionable bits
_STAT_QUES_VOLTAGE = 0x0001
_STAT_QUES_CURRENT = 0x0002
_STAT_QUES_TIME = 0x0004
_STAT_QUES_POWER = 0x0008
_STAT_QUES_TEMPERATURE = 0x0010
_STAT_QUES_FREQUENCY = 0x0020
_STAT_QUES_PHASE = 0x0040
_STAT_QUES_MODULATION = 0x0080
_STAT_QUES_CALIBRATION = 0x0100
_STAT_QUES_INST_SUMMARY = 0x2000
_STAT_QUES_COMMAND_WARNING = 0x4000
