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NikolasK-source/shm-modbus-signal-generator.py

Created June 28, 2023 08:19
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System time based signal generator for stdin-to-modbus-shm
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shm-modbus-signal-generator.py
#!/usr/bin/python3
# MIT License
#
# Copyright (c) 2023 Nikolas Koesling <nikolas@koesling.info>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import sys
import math
import time
import signal
import argparse
import os
#
# function = ^toggle
# f(x) = offset + scale * function((x + time-offset) * speed)
#
# function = toggle
# f(x) = rect((x + time-offset) * speed)
#
# x is generated from the current system time
#
__VERSION__ = '1.0.0'
def print_function(function:str):
if function == 'sin':
print(' 1| o ^ o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' |o o o')
print('--o-------------------------------o-------------------------------o------------>')
print(' 0| π/2 π o 3π/2 o 2π')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print('-1| o _ o')
elif function == 'cos':
print(' o 1^ o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print('--o---------------|---------------o-------------------------------o------------>')
print('-π/2 0| π/2 o π o 3π/2 2π')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' -1| o _ o')
elif function == 'nsin':
print(' 1| o ^ o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print('--o-------------------------------o-------------------------------o------------>')
print(' 0|o π/2 o π 3π/2 2π o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print(' | o o o')
print('-1| o _ o o')
elif function == 'ncos':
print(' 1| o ^ o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print(' | o o')
print('-π/2 | o o')
print('--o---------------|---------------o-------------------------------o------------>')
print(' o 0| o π/2 π 3π/2 o 2π')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o | o o')
print(' o-1_ o o')
elif function == 'rampdown':
print('1 o o o')
print(' | o o o o o')
print(' | o o o o o')
print(' | o o o o')
print('0 -|-----------o-----------o----->')
print(' 0 1 2')
elif function == 'rampup':
print('1 | o o')
print(' | o o o o')
print(' | o o o o o')
print(' | o o o o o')
print('0 -o-----------o-----------o----->')
print(' 0 1 2')
elif function == 'ramp':
print('1 | o')
print(' | o o')
print(' | o o o')
print(' | o o o')
print('0 -o-----------------------o----->')
print(' 0 1 2')
elif function == 'toggle':
print('1 o o o o o o o o o o o')
print(' | o o')
print(' | o o')
print(' | o o')
print('0 -|-----------o-o-o-o-o-o-o----->')
print(' 0 1 2')
else:
print(f'unknown function \"{function}\"', file=sys.stderr)
exit(os.EX_USAGE)
# end def
if __name__ == '__main__':
#### Argparse
parser = argparse.ArgumentParser(prog="signal-gen",
description="System time based signal generator for stdin-to-modbus-shm",
epilog='f(x = time.time()) = offset + scale * function((x + time-offset) * speed)')
parser.add_argument('-o', '--offset', type=float, nargs=1,default=0, help="function offset, ignored if function is toggle")
parser.add_argument('-s', '--scale', type=float, nargs=1,default=1, help="function scale, ignored if function is toggle")
parser.add_argument('-v', '--speed', type=float, nargs=1,default=1, help="function speed")
parser.add_argument('-d', '--delay', type=float, nargs=1, help="delay between calculations", default=0.1)
parser.add_argument('-e', '--endian', type=str, nargs=1, help="data type/endianess string (see stdin-to-modbus-shm)", default='')
parser.add_argument('-t', '--time_offset', type=float, nargs=1, default=0, help="system time offset in seconds")
parser.add_argument('-p', '--print', action='store_true', default=False, help="print function and exit")
parser.add_argument('--version', action='version', version=__VERSION__)
parser.add_argument('function', type=str, nargs=1, help="function that is calculated",
choices=['sin', 'cos', 'nsin', 'ncos', 'rampup', 'rampdown', 'ramp', 'toggle'])
parser.add_argument('register_type', type=str, nargs='?', help="register type (see stdin-to-modbus-shm)",
choices=['ai', 'ao', 'di', 'do'])
parser.add_argument('register', type=str, nargs='*', help="modbus register to write value")
args = parser.parse_args()
#### Setup
function = f'{args.function[0]}'
if args.print:
print_function(function)
exit(os.EX_OK)
if args.register_type is None:
print('no register type provided', file=sys.stderr)
exit(os.EX_USAGE)
if args.register is None:
print('no registers provided', file=sys.stderr)
exit(os.EX_USAGE)
regtype = f'{args.register_type[0]}'
offset = args.offset
scale = args.scale
speed = args.speed
delay = args.delay
if args.endian != '':
endian = f':{args.endian[0]}'
else:
endian = ''
time_offset = args.time_offset
try:
regs = [int(x, 0) for x in args.register]
except ValueError as e:
print(f"failed to parse registers: {e}")
exit(os.EX_USAGE)
signal.signal(signal.SIGINT, lambda NUM, _: exit(0))
signal.signal(signal.SIGTERM, lambda NUM, _: exit(0))
if function == 'sin':
fun = math.sin
elif function == 'cos':
fun = math.cos
elif function == 'nsin':
fun = lambda x: -math.sin(x)
elif function == 'ncos':
fun = lambda x: -math.cos(x)
elif function == 'rampdown':
fun = lambda x: 1.0 - (x - int(x))
elif function == 'rampup':
fun = lambda x: x - int(x)
elif function == 'ramp':
def ramp(x):
if int(x) % 2 == 0:
return x - int(x)
else:
return 1.0 - (x - int(x))
fun = ramp
elif function == 'toggle':
fun = lambda x: int(x) % 2
else:
print(f'unknown function \"{function}\"', file=sys.stderr)
exit(os.EX_USAGE)
#### main loop
f_old = None
while True:
x = time.time() + time_offset
f = offset + scale * fun(x * speed)
# print value only if it differs
if f != f_old:
f_old = f
for reg in regs:
print(f'{regtype}:0x{reg:x}:{f}{endian}')
time.sleep(delay)
# end while
# end if
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