Add single char wait time after flush to avoid RTU control pin timing…

… issue, see brainelectronics#68 and brainelectronics#72
hmaerki · Dec 24, 2023 · 8e8ed49 · 8e8ed49
1 parent 8bf8a3f
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diff --git a/changelog.md b/changelog.md
@@ -15,6 +15,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 <!-- ## [Unreleased] -->
 
 ## Released
+## [2.3.7] - 2023-07-19
+### Fixed
+- Add a single character wait time after flush to avoid timing issues with RTU control pin, see #68 and #72
+
 ## [2.3.6] - 2023-07-19
 ### Added
 - Add contribution guideline, see #67
@@ -303,8 +307,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - PEP8 style issues on all files of [`lib/uModbus`](lib/uModbus)
 
 <!-- Links -->
-[Unreleased]: https://github.com/brainelectronics/micropython-modbus/compare/2.3.6...develop
+[Unreleased]: https://github.com/brainelectronics/micropython-modbus/compare/2.3.7...develop
 
+[2.3.7]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.7
 [2.3.6]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.6
 [2.3.5]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.5
 [2.3.4]: https://github.com/brainelectronics/micropython-modbus/tree/2.3.4

diff --git a/examples/rtu_host_example.py b/examples/rtu_host_example.py
@@ -21,6 +21,8 @@
 # import modbus host classes
 from umodbus.serial import Serial as ModbusRTUMaster
 
+print("A")
+
 IS_DOCKER_MICROPYTHON = False
 try:
     import machine
@@ -32,7 +34,7 @@
     IS_DOCKER_MICROPYTHON = True
     import sys
 
-
+print("B")
 # ===============================================
 # RTU Slave setup
 slave_addr = 10             # address on bus of the client/slave
@@ -159,7 +161,7 @@
     starting_addr=coil_address,
     coil_qty=coil_qty)
 print('Status of COIL {}: {}'.format(coil_address, coil_status))
-time.sleep(1)
+# time.sleep(1)
 
 # WRITE COILS
 new_coil_val = 0
@@ -168,15 +170,15 @@
     output_address=coil_address,
     output_value=new_coil_val)
 print('Result of setting COIL {} to {}'.format(coil_address, operation_status))
-time.sleep(1)
+# time.sleep(1)
 
 # READ COILS again
 coil_status = host.read_coils(
     slave_addr=slave_addr,
     starting_addr=coil_address,
     coil_qty=coil_qty)
 print('Status of COIL {}: {}'.format(coil_address, coil_status))
-time.sleep(1)
+# time.sleep(1)
 
 print()
 
@@ -189,7 +191,7 @@
     register_qty=register_qty,
     signed=False)
 print('Status of HREG {}: {}'.format(hreg_address, register_value))
-time.sleep(1)
+# time.sleep(1)
 
 # WRITE HREGS
 new_hreg_val = 44
@@ -199,7 +201,7 @@
     register_value=new_hreg_val,
     signed=False)
 print('Result of setting HREG {} to {}'.format(hreg_address, operation_status))
-time.sleep(1)
+# time.sleep(1)
 
 # READ HREGS again
 register_value = host.read_holding_registers(
@@ -208,7 +210,7 @@
     register_qty=register_qty,
     signed=False)
 print('Status of HREG {}: {}'.format(hreg_address, register_value))
-time.sleep(1)
+# time.sleep(1)
 
 print()
 
@@ -220,7 +222,7 @@
     starting_addr=ist_address,
     input_qty=input_qty)
 print('Status of IST {}: {}'.format(ist_address, input_status))
-time.sleep(1)
+# time.sleep(1)
 
 print()
 
@@ -233,7 +235,7 @@
     register_qty=register_qty,
     signed=False)
 print('Status of IREG {}: {}'.format(ireg_address, register_value))
-time.sleep(1)
+# time.sleep(1)
 
 print()
 
@@ -248,7 +250,7 @@
     output_address=coil_address,
     output_value=new_coil_val)
 print('Result of setting COIL {}: {}'.format(coil_address, operation_status))
-time.sleep(1)
+# time.sleep(1)
 
 print()
 

diff --git a/heizung-Dockerfile.dezentral_rtu b/heizung-Dockerfile.dezentral_rtu
@@ -0,0 +1,13 @@
+# Build image
+# $ docker build -t micropython-client-rtu -f Dockerfile.client_rtu .
+#
+# Run image
+# $ docker run -it --rm --name micropython-client-rtu micropython-client-rtu
+
+FROM micropython/unix:v1.18
+
+# use "volumes" in docker-compose file to remove need of rebuilding
+# COPY ./ /home
+# COPY umodbus /root/.micropython/lib/umodbus
+
+CMD [ "micropython-dev", "-m", "heizung_rtu_dezentral" ]
diff --git a/heizung-Dockerfile.zentral_rtu b/heizung-Dockerfile.zentral_rtu
@@ -0,0 +1,13 @@
+# Build image
+# $ docker build -t micropython-host-rtu -f Dockerfile.host_rtu .
+#
+# Run image
+# $ docker run -it --rm --name micropython-host-rtu micropython-host-rtu
+
+FROM micropython/unix:v1.18
+
+# use "volumes" in docker-compose file to remove need of rebuilding
+# COPY ./ /home
+# COPY umodbus /root/.micropython/lib/umodbus
+
+CMD [ "micropython-dev", "-m", "heizung_rtu_zentral" ]
diff --git a/heizung-docker-compose-rtu.yaml b/heizung-docker-compose-rtu.yaml
@@ -0,0 +1,62 @@
+---
+
+#
+# build all non-image containers
+# $ docker-compose build
+# can be combined into one command to also start it afterwards
+# $ docker-compose up --build
+#
+
+version: "3.8"
+
+services:
+  micropython-dezentral:
+    build:
+      context: .
+      dockerfile: heizung-Dockerfile.dezentral_rtu
+    container_name: micropython-dezentral
+    volumes:
+      - ./:/home
+      - ./umodbus:/root/.micropython/lib/umodbus
+      - ./fakes:/usr/lib/micropython
+      - ./tests/ulogging.py:/root/.micropython/lib/ulogging.py
+    expose:
+      - "65433"
+    ports:
+      # reach "micropython-dezentral" at 172.25.0.2:65433, see networks
+      - "65433:65433"
+    networks:
+      serial_bridge:
+        # fix IPv4 address to be known and in the MicroPython scripts
+        # https://docs.docker.com/compose/compose-file/#ipv4_address
+        ipv4_address: 172.25.0.2
+
+  micropython-zentral:
+    build:
+      context: .
+      dockerfile: heizung-Dockerfile.zentral_rtu
+    container_name: micropython-zentral
+    volumes:
+      - ./:/home
+      - ./umodbus:/root/.micropython/lib/umodbus
+      - ./fakes:/usr/lib/micropython
+      - ./tests/ulogging.py:/root/.micropython/lib/ulogging.py
+    depends_on:
+      - micropython-dezentral
+    networks:
+      serial_bridge:
+        # fix IPv4 address to be known and in the MicroPython scripts
+        # https://docs.docker.com/compose/compose-file/#ipv4_address
+        ipv4_address: 172.25.0.3
+
+networks:
+  serial_bridge:
+    # use "external: true" if the network already exists
+    # check available networks with "docker network ls"
+    # external: true
+    driver: bridge
+    # https://docs.docker.com/compose/compose-file/#ipam
+    ipam:
+      config:
+        - subnet: 172.25.0.0/16
+          gateway: 172.25.0.1
diff --git a/heizung_rtu_dezentral.py b/heizung_rtu_dezentral.py
@@ -0,0 +1,149 @@
+#!/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 RTU client (slave) which can be requested for data or set with
+specific values by a host device.
+
+The RTU communication pins can be choosen freely (check MicroPython device/
+port specific limitations).
+The register definitions of the client as well as its connection settings like
+bus address and UART communication speed can be defined by the user.
+"""
+
+# import modbus client classes
+from umodbus.serial import ModbusRTU
+
+IS_DOCKER_MICROPYTHON = False
+try:
+    import machine
+    machine.reset_cause()
+except ImportError:
+    raise Exception('Unable to import machine, are all fakes available?')
+except AttributeError:
+    # machine fake class has no "reset_cause" function
+    IS_DOCKER_MICROPYTHON = True
+    import json
+
+
+# ===============================================
+# RTU Slave setup
+# act as client, provide Modbus data via RTU to a host device
+# ModbusRTU can get serial requests from a host device to provide/set data
+# check MicroPython UART documentation
+# https://docs.micropython.org/en/latest/library/machine.UART.html
+# for Device/Port specific setup
+#
+# RP2 needs "rtu_pins = (Pin(4), Pin(5))" whereas ESP32 can use any pin
+# the following example is for an ESP32.
+# For further details check the latest MicroPython Modbus RTU documentation
+# example https://micropython-modbus.readthedocs.io/en/latest/EXAMPLES.html#rtu
+rtu_pins = (25, 26)         # (TX, RX)
+slave_addr = 10             # address on bus as client
+baudrate = 9600
+uart_id = 1
+
+from machine import Pin
+import os
+from umodbus import version
+
+print('Using pins {} with UART ID {}'.format(rtu_pins, uart_id))
+
+client = ModbusRTU(
+    addr=slave_addr,        # address on bus
+    pins=rtu_pins,          # given as tuple (TX, RX)
+    baudrate=baudrate,      # optional, default 9600
+    # data_bits=8,          # optional, default 8
+    # stop_bits=1,          # optional, default 1
+    # parity=None,          # optional, default None
+    # ctrl_pin=12,          # optional, control DE/RE
+    uart_id=uart_id         # optional, default 1, see port specific docs
+)
+
+if IS_DOCKER_MICROPYTHON:
+    # works only with fake machine UART
+    assert client._itf._uart._is_server is True
+
+
+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')
+
+
+# common slave register setup, to be used with the Master example above
+register_definitions = {
+    "COILS": {
+        "RESET_REGISTER_DATA_COIL": {
+            "register": 42,
+            "len": 1,
+            "val": 0
+        },
+        "EXAMPLE_COIL": {
+            "register": 123,
+            "len": 1,
+            "val": 1
+        }
+    },
+    "HREGS": {
+        "EXAMPLE_HREG": {
+            "register": 93,
+            "len": 1,
+            "val": 19
+        }
+    },
+    "ISTS": {
+        "EXAMPLE_ISTS": {
+            "register": 67,
+            "len": 1,
+            "val": 0
+        }
+    },
+    "IREGS": {
+        "EXAMPLE_IREG": {
+            "register": 10,
+            "len": 1,
+            "val": 60001
+        }
+    }
+}
+
+# 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)
+
+# reset all registers back to their default value with a callback
+register_definitions['COILS']['RESET_REGISTER_DATA_COIL']['on_set_cb'] = \
+    reset_data_registers_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 RTU client on address {} at {} baud'.
+      format(slave_addr, baudrate))
+
+while True:
+    try:
+        result = client.process()
+    except KeyboardInterrupt:
+        print('KeyboardInterrupt, stopping RTU client...')
+        break
+    except Exception as e:
+        print('Exception during execution: {}'.format(e))
+
+print("Finished providing/accepting data as client")