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# -*- coding: utf-8 -*-
#
# PROFIBUS DP - Communication Processor PHY access library
#
# Copyright (c) 2016-2021 Michael Buesch <m@bues.ch>
#
# Licensed under the terms of the GNU General Public License version 2,
# or (at your option) any later version.
#
from __future__ import division, absolute_import, print_function, unicode_literals
from pyprofibus.compat import *
from pyprofibus.phy import *
from pyprofibus.fdl import FdlTelegram
from pyprofibus.util import *
import sys
try:
import serial
except ImportError as e:
if "PyPy" in sys.version and\
sys.version_info[0] == 2:
# We are on PyPy2.
# Try to import CPython2's serial.
import glob
sys.path.extend(glob.glob("/usr/lib/python2*/*-packages/"))
import serial
else:
raise e
try:
import serial.rs485
except ImportError:
pass
__all__ = [
"CpPhySerial",
]
class CpPhySerial(CpPhy):
"""pyserial based PROFIBUS CP PHYsical layer
"""
__slots__ = (
"__discardTimeout",
"__rxBuf",
"__serial",
)
PFX = "PHY-serial: "
def __init__(self, port, useRS485Class=False, *args, **kwargs):
"""port => "/dev/ttySx"
debug => enable/disable debugging.
useRS485Class => Use serial.rs485.RS485, if True. (might be slower).
"""
super(CpPhySerial, self).__init__(*args, **kwargs)
self.__discardTimeout = None
self.__rxBuf = bytearray()
try:
if useRS485Class:
if not hasattr(serial, "rs485"):
raise PhyError("Module serial.rs485 "
"is not available. "
"Please use useRS485Class=False.")
self.__serial = serial.rs485.RS485()
else:
self.__serial = serial.Serial()
self.__serial.port = port
self.__serial.baudrate = CpPhy.BAUD_9600
self.__serial.bytesize = 8
self.__serial.parity = serial.PARITY_EVEN
self.__serial.stopbits = serial.STOPBITS_ONE
self.__serial.timeout = 0
self.__serial.xonxoff = False
self.__serial.rtscts = False
self.__serial.dsrdtr = False
if useRS485Class:
self.__serial.rs485_mode = serial.rs485.RS485Settings(
rts_level_for_tx = True,
rts_level_for_rx = False,
loopback = False,
delay_before_tx = 0.0,
delay_before_rx = 0.0
)
self.__serial.open()
except (serial.SerialException, ValueError) as e:
raise PhyError("Failed to open "
"serial port:\n" + str(e))
def close(self):
try:
self.__serial.close()
except serial.SerialException as e:
pass
self.__rxBuf = bytearray()
super(CpPhySerial, self).close()
def __discard(self):
s = self.__serial
if s:
s.flushInput()
s.flushOutput()
if monotonic_time() >= self.__discardTimeout:
self.__discardTimeout = None
def __startDiscard(self):
self.__discardTimeout = monotonic_time() + 0.01
# Poll for received packet.
# timeout => In seconds. 0.0 = none, Negative = unlimited.
def pollData(self, timeout=0.0):
if timeout > 0.0:
timeoutStamp = monotonic_time() + timeout
ret = None
rxBuf = self.__rxBuf
ser = self.__serial
size = -1
getSize = FdlTelegram.getSizeFromRaw
while self.__discardTimeout is not None:
self.__discard()
if timeout > 0.0 and monotonic_time() >= timeoutStamp:
return None
try:
rxBufLen = len(rxBuf)
while True:
if rxBufLen < 1:
rxBuf.extend(ser.read(1))
elif rxBufLen < 3:
if size < 0:
size = getSize(rxBuf)
readLen = (size if size > 0 else 3) - rxBufLen
if readLen > 0:
rxBuf.extend(ser.read(readLen))
elif rxBufLen >= 3:
if size < 0:
size = getSize(rxBuf)
if size < 0:
if self.debug and rxBuf:
self._debugMsg("RX (fragment) %s" % bytesToHex(rxBuf))
rxBuf = bytearray()
self.__startDiscard()
raise PhyError("PHY-serial: "
"Failed to get received telegram size: "
"Invalid telegram format.")
if rxBufLen < size:
rxBuf.extend(ser.read(size - rxBufLen))
rxBufLen = len(rxBuf)
if rxBufLen == size:
ret = rxBuf
rxBuf = bytearray()
rxBufLen = 0
break
if (timeout == 0.0 or
(timeout > 0.0 and monotonic_time() >= timeoutStamp)):
break
except serial.SerialException as e:
if self.debug and rxBuf:
self._debugMsg("RX (fragment) %s" % bytesToHex(rxBuf))
rxBuf = bytearray()
self.__startDiscard()
raise PhyError("PHY-serial: Failed to receive "
"telegram:\n" + str(e))
finally:
self.__rxBuf = rxBuf
if self.debug and ret:
self._debugMsg("RX %s" % bytesToHex(ret))
return ret
def sendData(self, telegramData, srd):
if self.__discardTimeout is not None:
return
try:
if self.debug:
self._debugMsg("TX %s" % bytesToHex(telegramData))
self.__serial.write(telegramData)
except serial.SerialException as e:
raise PhyError("PHY-serial: Failed to transmit "
"telegram:\n" + str(e))
def setConfig(self, baudrate=CpPhy.BAUD_9600, rtscts=False, dsrdtr=False, *args, **kwargs):
wellSuppBaud = (9600, 19200)
if baudrate not in wellSuppBaud and not isMicropython:
# The hw/driver might silently ignore the baudrate
# and use the already set value from __init__().
self._warningMsg("The configured baud rate %d baud "
"might not be supported by the hardware. "
"Note that some hardware silently falls back "
"to 9600 baud for unsupported rates. "
"Commonly well supported baud rates by serial "
"hardware are: %s." % (
baudrate,
", ".join(str(b) for b in wellSuppBaud)))
try:
if baudrate != self.__serial.baudrate or rtscts != self.__serial.rtscts or dsrdtr != self.__serial.dsrdtr:
self.__serial.close()
self.__serial.baudrate = baudrate
self.__serial.rtscts = rtscts
self.__serial.dsrdtr = dsrdtr
self.__serial.open()
self.__rxBuf = bytearray()
except (serial.SerialException, ValueError) as e:
raise PhyError("Failed to set CP-PHY "
"configuration:\n" + str(e))
self.__setConfigPiLC(baudrate)
super(CpPhySerial, self).setConfig(baudrate=baudrate,
rtscts=rtscts,
dsrdtr=dsrdtr,
*args, **kwargs)
def __setConfigPiLC(self, baudrate):
"""Reconfigure the PiLC HAT, if available.
"""
try:
import libpilc.raspi_hat_conf as raspi_hat_conf
except ImportError as e:
return
if not raspi_hat_conf.PilcConf.havePilcHat():
return
try:
conf = raspi_hat_conf.PilcConf()
conf.setBaudrate(baudrate / 1000.0)
except raspi_hat_conf.PilcConf.Error as e:
raise PhyError("Failed to configure PiLC HAT:\n%s" %\
str(e))
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