beyonlo
commented
1 year ago @MartiMan79 I think that your problem is just about the network and not about the ModBus.
I just changed your second pasted code and put that function (def w5x00_init():) that start the network and call it for wait to config the ETH, like as works in your HTTP example. After I put that fixed IP local_ip = '192.168.0.210'. I think this code below can works - I do not test it because I have no RPi Pico.
#!/usr/bin/env python3
# -*- coding: UTF-8 -*-
"""
Main script
Do your stuff here, this file is similar to the loop() function on Arduino
Create a Modbus TCP client (slave) which can be requested for data or set with
specific values by a host device.
The TCP port and IP address can be choosen freely. The register definitions of
the client can be defined by the user.
"""
# system packages
import time
# import modbus client classes
from umodbus.tcp import ModbusTCP
from machine import Pin,SPI
IS_DOCKER_MICROPYTHON = False
try:
import network
except ImportError:
IS_DOCKER_MICROPYTHON = True
import json
#W5x00 chip init
def w5x00_init():
spi=SPI(0,2_000_000, mosi=Pin(19),miso=Pin(16),sck=Pin(18))
nic = network.WIZNET5K(spi,Pin(17),Pin(20)) #spi,cs,reset pin
nic.active(True)
#None DHCP
nic.ifconfig(('192.168.0.210','255.255.255.0','192.168.0.1','8.8.8.8'))
#DHCP
#nic.ifconfig('dhcp')
print('IP address :', nic.ifconfig())
while not nic.isconnected():
time.sleep(1)
print(nic.regs())
# ===============================================
if IS_DOCKER_MICROPYTHON is False:
# connect to a network
w5x00_init()
#
# ===============================================
# TCP Slave setup
tcp_port = 502 # port to listen to
if IS_DOCKER_MICROPYTHON:
local_ip = '192.168.0.210' # static Docker IP address
else:
# set IP address of the MicroPython device explicitly
# local_ip = '192.168.4.1' # IP address
# or get it from the system after a connection to the network has been made
local_ip = '192.168.0.210'
# ModbusTCP can get TCP requests from a host device to provide/set data
client = ModbusTCP()
is_bound = False
# check whether client has been bound to an IP and port
is_bound = client.get_bound_status()
if not is_bound:
client.bind(local_ip=local_ip, local_port=tcp_port)
def my_holding_register_set_cb(reg_type, address, val):
print('Custom callback, called on setting {} at {} to: {}'.
format(reg_type, address, val))
def my_holding_register_get_cb(reg_type, address, val):
print('Custom callback, called on getting {} at {}, currently: {}'.
format(reg_type, address, val))
print('Custom callback, called on getting {} at {}, currently: {}'.
format(reg_type, address, val))
# any operation should be as short as possible to avoid response timeouts
new_val = val[0] + 1
# It would be also possible to read the latest ADC value at this time
# adc = machine.ADC(12) # check MicroPython port specific syntax
# new_val = adc.read()
client.set_ireg(address=address, value=new_val)
print('Incremented current value by +1 before sending response')
def reset_data_registers_cb(reg_type, address, val):
# usage of global isn't great, but okay for an example
global client
global register_definitions
print('Resetting register data to default values ...')
client.setup_registers(registers=register_definitions)
print('Default values restored')
# commond slave register setup, to be used with the Master example above
register_definitions = {
"HREGS": {
"EXAMPLE_HREG": {
"register": 93,
"len": 1,
"val": 19
}
}
}
# alternatively the register definitions can also be loaded from a JSON file
# this is always done if Docker is used for testing purpose in order to keep
# the client registers in sync with the test registers
if IS_DOCKER_MICROPYTHON:
with open('registers/example.json', 'r') as file:
register_definitions = json.load(file)
# add callbacks for different Modbus functions
# each register can have a different callback
# coils and holding register support callbacks for set and get
register_definitions['HREGS']['EXAMPLE_HREG']['on_set_cb'] = \
my_holding_register_set_cb
register_definitions['HREGS']['EXAMPLE_HREG']['on_get_cb'] = \
my_holding_register_get_cb
print('Setting up registers ...')
# use the defined values of each register type provided by register_definitions
client.setup_registers(registers=register_definitions)
# alternatively use dummy default values (True for bool regs, 999 otherwise)
# client.setup_registers(registers=register_definitions, use_default_vals=True)
print('Register setup done')
print('Serving as TCP client on {}:{}'.format(local_ip, tcp_port))
while True:
try:
result = client.process()
except KeyboardInterrupt:
print('KeyboardInterrupt, stopping TCP client...')
break
except Exception as e:
print('Exception during execution: {}'.format(e))
print("Finished providing/accepting data as client")
MartiMan79
brainelectronics
Dear all, I'm trying to realize a cheap solution for dimming LEDs with the onboard PWM. This will be controlled by a PLC over ModbusTCP but I'm struggling to get the WIZnet RP2040-HAT-MicroPython code implemented into this example...
I receive a [Errno 22] EINVAL error and not capable to solve it as I have no experience with coding.
This is the code of the WIZnet HTTP server example that works on my Pico:
This is the code I ended up with combining the 2:
PLC Engineer exploring new fields is thanking you all in advance!