Crate roboplc

RoboPLC

RoboPLC is an ultimate pack of a framework and tools for creating real-time micro-services, PLCs and industrial-grade robots in Rust.

The crate is designed to let using all its components both separately and together.

RoboPLC is a part of EVA ICS industrial automation platform.

Technical documentation

Available at https://info.bma.ai/en/actual/roboplc/index.html

Examples

Can be found at https://github.com/roboplc/roboplc/tree/main/examples

DataBuffer

buf::DataBuffer covers a typical data exchange pattern when data frames are collected (cached) from a single or multiple producers, then taken by a single consumer in bulk and submitted, e.g. into a local database or into an external bus.

• always has got a fixed capacity

• thread-safe out-of-the-box

• frames may be forcibly pushed, overriding the previous ones, like in a ring-buffer.

Hub

hub::Hub implements a data-hub (in-process pub/sub) model, when multiple clients (usually thread workers) exchange data via a single virtual bus instead of using direct channels.

This brings some additional overhead into data exchange, however makes the architecture significantly clearer, lowers code support costs and brings additional features.

• classic pub/sub patterns with no data serialization overhead

• based on pchannel which allows to mix different kinds of data and apply additional policies if required

• a fully passive model with no “server” thread.

pdeque and pchannel

A policy-based deque pdeque::Deque is a component to build policy-based channels.

pchannel is a channel module, based on the policy-based deque.

Data policies supported:

• Always a frame is always delivered
• Latest a frame is always delivered, previous are dropped if no room (acts like a ring-buffer)
• Optional a frame can be skipped if no room
• Single a frame must be delivered only once (the latest one)
• SingleOptional a frame must be delivered only once (the latest one) and is optional

Additionally, components support ordering by data priority and automatically drop expired data if the data type has got an expiration marker method implemented.

pchannel is a real-time safe channel, mean it may be not so fast as popular channel implementations (it may be even slower than channels provided by std::sync::mpsc). But it is completely safe for real-time applications, mean there are no spin loops, data is always delivered with minimal latency and threads do not block each other.

Real-time

thread_rt::Builder provides a thread builder component, which extends the standard thread builder with real-time capabilities: scheduler policies and CPU affinity (Linux only).

supervisor::Supervisor provides a lightweight task supervisor to manage launched threads.

Controller

controller::Controller is the primary component of mixing up all the functionality together.

I/O

io module provides a set of tools to work with field devices and SCADA buses.

Currently supported:

• Modbus (RTU/TCP) via io::modbus (Modbus client/master example, Modbus server/slave example), requires modbus crate feature.

• Raw UDP in/out via io::raw_udp (Raw UDP in/out example)

• Subprocess pipes via io::pipe (Subprocess pipe example)

• EVA ICS EAPI in/out via io::eapi (EVA ICS example), requires eapi crate feature.

Using on other platforms

The components thread_rt, supervisor and controller can work on Linux machines only.

Re-exports

• pub use parking_lot_rt as locking;
• pub use metrics;

Modules

• buf
  Event buffers
• comm
  Reliable TCP/Serial communications
• controller
  Controller and workers
• hub
  In-process data communication pub/sub hub, synchronous edition
• hub_async
  In-process data communication pub/sub hub, asynchronous edition
• io
  I/O
• pchannel
  Policy-based channels, synchronous edition
• pchannel_async
  Policy-based channels, asynchronous edition
• pdeque
  Policy-based data storages
• prelude
• semaphore
  A lighweight real-time safe semaphore
• supervisor
  Task supervisor to manage real-time threads
• thread_rt
  Real-time thread functions to work with supervisor::Supervisor and standalone
• time
  Various time tools for real-time applications
• ttlcell
  A memory cell with an expiring value

Macros

• event_matches
  A macro which can be used to match an event with enum for Hub subscription condition

Enums

• DeliveryPolicy
  Data delivery policies, used by hub::Hub, pchannel::Receiver and pdeque::Deque
• Error
  The crate error type
• LevelFilter
  An enum representing the available verbosity level filters of the logger.

Traits

• DataDeliveryPolicy
  Implements delivery policies for own data types

Functions

• configure_logger
  Configures stdout logger with the given filter. If started in production mode, does not logs timestamps
• critical
  Immediately kills the current process and all its subprocesses with a message to stderr
• is_production
  Returns true if started in production mode (as a systemd unit)
• metrics_exporter
  Returns Prometheus metrics exporter builder
• setup_panic
  Sets panic handler to immediately kill the process and its childs with SIGKILL. The process is killed when panic happens in ANY thread
• suicide
  Terminates the current process and all its subprocesses in the specified period of time with SIGKILL command. Useful if a process is unable to shut it down gracefully within a specified period of time.

Type Aliases

• Result

Derive Macros

• DataPolicy
  Automatically implements the DataDeliveryPolicy trait for an enum