Laboratorio Protocolo ModBus

El siguiente script realiza una lectura cada 2 segundos del holding reg 0 y lo grafica. Debemos cambiar el host por la dirección del host que vamos a consultar.

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import datetime as dt

import random

import matplotlib.pyplot as plt

import matplotlib.animation as animation

from pyModbusTCP.client import ModbusClient

# Create figure for plotting

fig = plt.figure()

ax = fig.add_subplot(1, 1, 1)

xs = []

ys = []

# This function is called periodically from FuncAnimation

def animate(i, xs, ys):

    # Read temperature (Celsius) from TMP102

    temp_c=regs_list=client.read_holding_registers(0,1)

    print("registro leido:")

    print(temp_c)

    #round(5, 2)

    # Add x and y to lists

    xs.append(dt.datetime.now().strftime('%H:%M:%S'))

    ys.append(temp_c)

    # Limit x and y lists to 20 items

    xs = xs[-20:]

    ys = ys[-20:]

    # Draw x and y lists

    ax.clear()

    ax.plot(xs, ys)

    # Format plot

    plt.xticks(rotation=45, ha='right')

    plt.subplots_adjust(bottom=0.30)

    plt.title('Lectura de Servidor Modbus TCP ')

    plt.ylabel('Temperature (deg C)')

# Set up plot to call animate() function periodically

ani = animation.FuncAnimation(fig, animate, fargs=(xs, ys), interval=2000)

client = ModbusClient(host='localhost', port=502, auto_open=True, auto_close=True)

client.open()

plt.show()