A little industrial HMI with a backgroung img and an overlay of modbus data

tk_modbus_hmi.py

#!/usr/bin/python3
# -*- coding: utf-8 -*-
from tkinter import *
from pyModbusTCP.client import ModbusClient
import time

# some const
SERVER_HOST = "192.168.0.64"
SERVER_PORT = 502

# some global vars
# define modbus server host, port
c = ModbusClient()
c.host(SERVER_HOST)
c.port(SERVER_PORT)
# Tk
root=Tk()

# load backgroung image (640x480)
img_background=PhotoImage(file="bg_hmi.gif")

# build canvas and fill it
cnv = Canvas(root, width=640, height=480)
item = cnv.create_image(0, 0, anchor=NW, image=img_background)
cnv.pack()

# add overlay with dynamic data
p_amont_vl = cnv.create_text(256, 298, text="##", font=("Helvetica", 8),
                                 fill="orange")
p_aval_vl = cnv.create_text(256, 312, text="##", font=("Helvetica", 8),
                                fill="orange")
p_aval_cp = cnv.create_text(256, 326, text="##", font=("Helvetica", 8),
                                fill="orange")

#Button(root, text="more pressure", command=more_p).pack()
#cnv.create_oval(100, 200, 120, 220, outline='black', fill='red')

# main modbus cycle
def mbus_cycle():
    if not c.is_open():
        c.open()
    if c.is_open():
        reg=c.read_holding_registers(0,20)
        if reg:
          cnv.itemconfig(p_amont_vl, text=reg[0], fill="red")
          cnv.itemconfig(p_aval_vl, text=reg[1], fill="red")
          cnv.itemconfig(p_aval_cp, text=reg[2], fill="red")
    else:
        cnv.itemconfig(p_amont_vl, text="##", fill="orange")
        cnv.itemconfig(p_aval_vl, text="##", fill="orange")
        cnv.itemconfig(p_aval_cp, text="##", fill="orange")
    # redo after 500ms
    root.after(500, mbus_cycle)

# init modbus cycle
mbus_cycle()
# Tk main loop
root.wm_title('Test HMI modbus with Python/Tk')
#root.wm_attributes('-fullscreen', True)
root.mainloop()