ABB JOKAB SAFETY Pluto series safety PLC

ABB JOKAB SAFETY Pluto series safety PLC

The importance of safety control systems in the field of industrial automation is self-evident. It is not only a key defense line to ensure personnel safety, but also an important support to ensure production continuity. The Pluto safety PLC series launched by ABB JOKAB SAFETY has brought revolutionary changes to the design of safety systems with its unique "All Supervisor" concept and innovative dynamic signal technology.

Pluto is not only a Safety Programmable Logic Controller (Safety PLC), but also a new design concept for safety systems. It simplifies the construction process of complex safety systems while achieving the highest safety levels - EN 954-1/EN ISO 13849-1 Category 4, PL e, and IEC/EN 61508 SIL 3. This article will comprehensively analyze the technical connotation and application value of Pluto safety PLC from multiple dimensions such as product concept, core features, hardware series, software tools, network integration, and application cases.

1. The concept of "All Supervisor": redefining the architecture of security systems

1.1 Limitations of Traditional Safety PLCs

Traditional safety PLC systems typically adopt a "master-slave" architecture, where a single supervisor is responsible for coordinating and managing multiple slave stations. In this architecture, communication between slave stations must be carried out through the master controller, which increases the complexity and response time of the system, while also creating the risk of single point of failure.

1.2 Pluto's Innovative Concept

Pluto has disrupted this traditional architecture. In the Pluto system, there is no "master-slave" relationship, and every Pluto unit connected to the same secure bus is a "supervisor" unit. Each Pluto can see the input and output status of other Pluto and make independent decisions based on the local security environment.

This concept brings significant advantages:

Simplified communication: Any Pluto can directly read the input state of other Pluto, as simple as reading its own input

Flexible system expansion: up to 32 Pluto units can be connected, and the system scale can be expanded from 20 I/O points (B20 series) to 390 I/O points (B46 series)

Modular machine design: Each machine module can be equipped with an independent Pluto, and the modules are interconnected through a secure bus to form a complete security system

High availability: Each Pluto makes independent decisions, and a single point of failure will not cause the entire system to crash

2. Dynamic signal technology: achieving maximum safety with minimal input

2.1 Limitations of Traditional Static Signals

The traditional static signal (+24V or 0V) implementation of a two channel safety structure requires two independent input channels. When multiple safety devices need to be connected in series, the number of input points will increase sharply, causing a shortage of controller I/O points.

2.2 Dynamic Signal Principle

Pluto uses innovative dynamic signal technology to achieve the highest level of security for a single channel by sending square wave signals and evaluating them upon return. Its working principle is as follows:

Pluto generates three unique dynamic signals: A pulse, B pulse, or C pulse

When the signal passes through safety devices such as light curtains, emergency stop buttons, and safety switches, the signal is reversed once for each device it passes through

Pluto receives the return signal and compares it with the expected signal

If the signal does not meet expectations (such as short circuit, signal loss, or incorrect signal type), Pluto immediately cuts off the safety output

2.3 Advantages of Dynamic Signals

Extremely high input efficiency: In dynamic signal systems, up to 10 safety sensors can be connected in series to one input channel while maintaining safety levels of Category 4, PL e, and SIL 3. This means that a Pluto B20 (8 safety inputs) can connect up to 80 safety sensors, while a Pluto B46 (24 safety inputs) can connect up to 240 safety sensors.

Comprehensive fault detection: The dynamic signal system can detect various fault situations, including:

Short circuit between sensors

Short circuit between sensor input and output

Short circuits between different dynamic signals

Short circuit to power or ground

2.4 Flexible combination of static and dynamic

Pluto's input can be configured as either a dynamic signal input or a static signal input, meeting the needs of different types of safety devices:

Dynamic input: Eden non-contact sensor, SPOT light curtain, Tina adapter, etc. suitable for ABB JOKAB SAFETY, can achieve the highest single channel safety level

Static input: suitable for traditional mechanical switches, requiring two input channels to achieve the highest safety level

3. Hardware series: meet diverse application needs

Pluto offers multiple models to adapt to various application scenarios ranging from standalone devices to large-scale integrated systems.

3.1 Overview of Basic Models

Model Safety Input Non safety Output/Safety Input Safety Relay Output Safety Transistor Output Safety Bus Special Functions

Pluto A20 v2 8 8 2 2 2 optional current monitoring

Pluto B20 v2 8 8 2 2 2 standard configuration-

Pluto B22 14 8- Standard-

Pluto D20 8 8 2 2 comes standard with 4 analog inputs

Pluto S20 v2 8 2 2 2- Independent Unit

Pluto B46 v2 24 16 4 2 standard-

Pluto D45 24 15 4 2 comes standard with 8 analog/4 counting channels

Pluto S46 v2 24 16 4 2- Independent Unit

Pluto AS-i v2 4 4 2 2 2 comes standard with AS-i bus

Pluto B42 AS-i 20 16 4 2 comes standard with AS-i bus

3.2 Detailed Explanation of Featured Models

Pluto A20 v2: Equipped with unique current monitoring function, it can monitor the current of IQ16 and IQ17 ports (0-1.0A ± 10%). This feature is particularly suitable for ensuring the proper functioning of the muting lamp. It should be noted that the current monitoring function does not have independent redundancy, so if used for safety functions, it must be used dynamically, that is, to read and evaluate the current separately when outputting enable and disable.

Pluto D20 and D45: Added analog input function, suitable for situations where monitoring of analog safety signals is required. D20 is equipped with 4 safety analog inputs, D45 is equipped with 8 safety analog inputs, which can be configured as:

Normal secure input

0-10V analog input

4-20mA analog input

To achieve SIL 3/PL e safety level, two sensors need to be connected in parallel, each with an input channel.

Pluto D45 counting input: The four inputs IA0-IA3 of D45 can be configured as high-speed counting inputs, with a maximum frequency of 14000 Hz, supporting two counting modes:

Up counting: suitable for speed monitoring, can be connected to inductive sensors, photoelectric sensors, or incremental encoders

Up/Down Counting: The sensor needs to generate A/B pulses with a phase difference of 90 °, which can simultaneously monitor speed and direction

3.3 Unique Design of IQ Port

Pluto's IQ (input/output) port is a highly innovative feature, with one terminal configurable to:

Safe input: Same as I port function

Non safety output: used to control non safety functions such as indicator lights and status signals

Simultaneously serving as both input and output: for example, the reset button (input) with indicator light (output) can be implemented with just one terminal, greatly saving I/O points

4. Pluto Security Bus: A High Performance Distributed Security Network

4.1 Bus characteristics

The Pluto security bus is based on the CAN physical layer and uses proprietary security protocols, with the following characteristics:

Number of nodes: up to 32 Pluto units

Bus speed: 100, 125, 200, 250, 400, 500, 800, 1000 kb/s optional

Transmission distance: up to 600 meters at minimum speed and 150 meters at 400 kb/s speed

Electrical isolation: The bus interface is electrically isolated from the internal circuit to improve anti-interference capability

4.2 Bus Expansion and Bridge

Through Gateway devices (GATE-D2 or GATE-C2), it is possible to achieve:

Bus length extension: Divide the secure bus into multiple network segments, breaking through the length limit of a single cable segment

Different speed network segments: Different network segments can use different communication speeds to optimize performance

Information filtering: Filter unnecessary information, reduce network segment load, and allow longer cables

4.3 Integration with other buses

Pluto can seamlessly integrate into various industrial network environments through Gateway series devices

GATE-P2: PROFIBUS DP Gateway

GATE-D2: DeviceNet Gateway

GATE-C2: CANopen gateway

GATE-E2: Ethernet gateway, supporting PROFINET, EtherNet/IP, Modbus TCP

The Gateway device adopts a compact 22.5mm width design and can be installed on DIN rails. It can be configured through DIP switches and can be put into use without programming tools.

5. Pluto Manager: An intuitive secure programming tool

5.1 Software Overview

Pluto Manager is a programming software designed specifically for Pluto safety PLC, which is provided free of charge with the product and can be downloaded from the ABB website. The software uses ladder diagram programming language, combined with T Ü V certified functional blocks, greatly simplifying the development of safety functions.

5.2 Systematic workflow

Pluto Manager provides a clear three-step project development process:

Step 1: I/O Configuration

Define each Pluto unit

Configure the signal type of the input port (dynamic/static)

Purpose of configuring IQ port (input/output/bidirectional)

Step 2: Variable Naming

Define meaningful names for input (I), output (Q), hold memory (M), global auxiliary memory (GM), and registers (R)

Using names instead of actual addresses in PLC programs to improve readability and maintainability

Step 3: Ladder diagram programming

Building secure logic using named variables

Rich instruction set including timers, arithmetic operations, sequence control, etc

Download the project to Pluto via programming cable

The program is automatically distributed to all Pluto units in the project through the bus

5.3 Pre defined Function Block Library

Pluto Manager includes multiple T Ü V certified functional blocks, covering common safety applications:

Two channel safety input function (with startup, reset, and test inputs)

Single channel secure input function

Dual hand control function

Bypass function

Shielding lamp control function

Safe absolute value encoder function

Electronic cam function

6. Safety encoder and positioning monitoring

6.1 Safety Absolute Value Encoder

Pluto can be connected to a dedicated secure absolute value encoder for secure position and velocity monitoring. The encoder is directly connected to the Pluto safety bus and supports:

Single cycle encoder (RSA 597): 13 bit resolution, 8192 positions/cycle

Multi turn encoder (RSA 698): 25 bit total resolution (13 bits/turn+12 turns)

Hollow shaft encoder (RHA 597/698): suitable for direct installation on the motor shaft

6.2 Function Block Support

Pluto Manager provides specialized functional blocks for processing encoder signals:

Safe Encoder: Process two single loop encoders to generate safe position and velocity values

Safe Encoder Multiturn: Process two multi turn encoders to generate safe position and velocity values

Encoder Cam: Electronic cam function that activates output within a specific position range

6.3 Application Scenarios

Security encoders are widely used in:

Longmen robot position monitoring

Industrial robot safety zone restrictions

Eccentric press electronic cam

Overspeed monitoring

Static state monitoring

7. Application case: Robot unit safety system

The document provides a complete example of a robot unit safety system, demonstrating the application of Pluto in multi device collaboration.

7.1 System Architecture

Pluto 0 (robot unit): Connect emergency stop button, unit door lock sensor, reset button

Pluto 1 (machining machine): Connect machine emergency stop, protective door lock sensor, reset button

Two Pluto devices are interconnected through a secure bus and share status information

7.2 Safety Features

Emergency stop priority: When the emergency stop button is triggered, both the robot and the machine stop simultaneously

Partition control: When the machine tool protective door is closed, the robot and machine tool are divided into two independent safety zones; When the machine tool protective door is opened, it merges into one safety zone

Reset management: After the door is opened, the system must be reset through the reset button outside the door to prevent accidental startup

7.3 Global Variable Communication

The Pluto system supports global variables (GM) for sharing security states between different Pluto units:

GM0.0 (Pluto 0): Emergency stop status is normal

GM1.0 (Pluto 1): Emergency stop status is normal

GM1.1 (Pluto 1): Machine tool protective door closed

Through global variables, each Pluto can obtain the status of other units and make local decisions based on it.