The OpenPLC team recently developed a new hardware layer called Python SubModule or just simply PSM. The description is this: "PSM is a powerful bridge that connects OpenPLC core to Python. You can use PSM to write your own OpenPLC driver in pure Python."

We start to test this new cool feature and we share with you the setup process:

You need to install ioplus python library for python3 since PSM use python3

~$ sudo apt-get update
~$ sudo apt-get install build-essential python3-pip python3-dev python3-smbus git
~$ git clone https://github.com/SequentMicrosystems/ioplus-rpi.git
~$ cd ioplus-rpi/python/ioplus/
~/ioplus-rpi/python/ioplus$ sudo python3 setup.py install

Install OpenPLC on Raspberry, instructions here
In the OpenPLC web server go to the Hardware tab and select Python on Linux (PSM). You will see a text editor with some python code written in it, here some things to do for controlling the Home Automation Card:
Import the library:
import libioplus
Read some inputs in update_inputs() funtion. We read all the 8 optocoupled digital inputs and all 8 analog inputs and update PLC variables:

def update_inputs():
   #Read optocoupled inputs
   val = libioplus.getOpto(0)
   for i in range(8):
       var_state = False
       if val & (1 << i) != 0:
           var_state = True
       psm.set_var("IX0." + str(i), var_state)#move OPTO state to IX0.0 .. IX0.7
   for i in range(8):
       valAdc = libioplus.getAdcV(0, i+1)
       psm.set_var("IW" + str(i), int(1000 * valAdc)) 

#Update adc in value (mV) IW0 .. IW7 

Write some outputs on update_outputs() function. Relays from variables QX0.0 .. QX0.7 and DAC channels from QW0 .. QW3 :

def update_outputs():
   val = 0
   for i in range(8):
       a = psm.get_var("QX0." + str(i))
       if a == True:
           val+= 1 << i
   libioplus.setRelays(0, val)
   for i in range(4):
       val = psm.get_var("QW" + str(i))# DAC value in mV
       if val < 0:
           val = 0
       if val > 10000:
           val = 10000
       libioplus.setDacV(0, i+1, val/1000.0)

In the main loop, the only thing you might want to do is to adjust the PSM cycle time.You can download an OpenPLC project that use the Home Automation PSM integration. Please folow the tutorial on the OpenPLC website to generate and upload the ".st" file. Now you can access relays, optocoupled digital inputs, the voltage in and voltage outputs thru PLC variables, below you see screen capture with monitoring our variables: