ATWG 0.1.1

Various Temperature Waveform Generator for Climate Chambers

ATWG

Arbitrary Temperature Waveform Generator

A various waveform shapes creating python script to control a climate chamber via PC.

Releases

Version	Date	Source	Change log
latest		latest.zip
v0.1.1	2021-02-01	v0.1.1.zip	pypi.org published
v0.1.0	2020-03-09	v0.1.0.zip	initial draft

Supported climate chambers

• Espec Corp SH-641
  • RS232 communication interface
  • Espec S-2 controller

Command line interface

Options

Option	Description	Args
--sine	select sine as used waveform
--trapezoid	select trapezoid as used waveform
--minTemp=myVal	sets minimal temperature value
--maxTemp=myVal	sets maximal temperature value
[--invert]	start with lower part of wave
[--period=1h]	period of waveform	d:hh:mm:ss, h, m, s
[--startTemp=25]	waves start temperature	start temperature of wave
[--riseTime=0]	positive slew rate, used by '--trapezoid'	degree/time, T(min->max); 5C/h, 120min
[--fallTime=0]	negative slew rate, used by '--trapezoid'	degree/time, T(max->min); 5C/h, 120min
[--chamber=SIM]	used chamber	SIM, ESPEC_SH641
[--itfCfgFile=]	chambers interface configuration	default

Example

This example starts the waveform generator in the simulation mode. The sine wave has a minimal value of 10°C, a maximum of 60°C and s start value of 30°C. A full period needs one hour.

run ./ATWG/ATWG.py --sine --chamber=SIM --minTemp=10 --maxTemp=60 --startTemp=30 --period=1h

Output

Following output is written to the command line interface while the script is active:

Arbitrary Temperature Waveform Generator

  Chamber
    State    : Run /
    Type     : SIM
    Tmeas    : +30.02 °C
    Tset     : +30.06 °C

  Waveform
    Shape    : sine
    Tmin     : +10.00 °C
    Tmax     : +60.00 °C
    Period   : 1h
    Gradient : +2.57 °C/m


Press 'CTRL + C' for exit

Chamber driver only

Espec SH641

sh_641_drv.py realizes the interface to the climate chamber. Following instruction listing controls the chamber:

import ATWG.driver.espec.sh_641_drv as sh_641_drv # import driver

myChamber = especShSu()                           # call class constructor
myChamber.open()                                  # open with interface defaults
print(myChamber.get_clima())                      # get current clima
myChamber.start()                                 # start chamber
myChamber.set_clima(clima={'temperature': 25})    # set temperature value
myChamber.stop()                                  # stop chamber
myChamber.close()                                 # close handle

The open procedure accepts as argument a .yml file with the chamber (RS232) configuration. In case of no argument defaults are used.