Q & A on Mitsubishi's Q Series

Did you know Q Series provides a way to make automation technologies work together as one integrated platform?

When facing automation challenges, a key issue is integrating different types of control schemes. How should a PC be integrated with sequence control? How can the motion controller be connected to the rest of the system? How will the process control work alongside the sequence control?

In the past, hours of engineering time and development dollars were spent on identifying suitable vendors and appropriate products, then trying to figure out how to make them all work together. This was often a costly and frustrating way to work, leading to cost overruns and missed deadlines. With today''s relentless competition, this approach has a limited future. So what alternative is there?

Mitsubishi saw the problems inherent in the old way. The Q Series Automation Platform is a way to take separate control disciplines and combine them on the same platform, being sure they will function together. With four different CPU options, using each separately or combined, Q Series covers all system types with a single flexible platform:

• PC CPU. Put a standard Windows®-based PC on the controller rack in a compact, rugged industrial format. Use Visual Basic®, Visual C++®, etc. for system control


• Sequence CPUs. Cover all traditional PLC-based applications while offering new capabilities such as Structured Text and Sequential Function Chart programming, combined with tools to configure your system with no programming.


• Motion CPUs. Control up to 96 axes of digital servos directly; no intervening control modules. Use an innovative graphical programming system that duplicates your system with virtual mechanical components.


• Process CPUs. Comprehensive array of process control functions, supported by industry standard IEC function block programming.

The true power of the Q Series Automation Platform lies in the way these different controller types can be mixed and matched on the same controller platform, while still being able to offer complete interoperability. You are no longer forced into days of engineering time trying to make your motion controller work with your PLC. No frustration to endure because your PC can''t be made to work with your I/O networks. With Q Series, these challenges have already been addressed, and you just need to concentrate on how you''re going to get the system designed, running, and out the door.

Did you know Q Series provides a way to get your system engineered faster while making it easier to maintain?

Faster system development = fewer engineering dollars invested.

In today''s economic environment, getting more done in less time is the norm. If you are looking to develop a sequence control application, with our GX Developer suite of development tools, the Q Series Automation Platform supports this goal in a number of ways:

• Freedom from busywork. In the past, significant engineering time and effort was necessary to bring a controller to a point where it was ready to be programmed. With Q Series, Intelligent Function Utilities offer simple menu driven configuration of given system components, without programming. Similarly, network configuration and communications generally are also program free, saving more development work. An additional benefit is that Q Series has all the necessary network configuration tools built into the GX Developer development suite as standard. There are no other programming packages to buy, and no hidden costs.


• Program flexibility. When used for sequence control, Q Series offers a variety of programming methods that offer increased productivity when compared to conventional ladder logic:
  * Structured Text (ST). Write sequence programs in a more modern programming language format using constructions such as IF THEN ELSE, and device labels. Widen the pool of potential programming staff by not requiring knowledge of relay logic circuits to program the system. ST also broadens the appeal of Q Series to industries that do not have an established ladder logic tradition.
  * Sequential Function Chart (SFC). SFC offers a graphical flowchart style method of programming. Relate system program to the actual flow of operations, rather than meaningless lines of code. The graphical presentation of the program also means troubleshooting can take place faster, as following the operation of the system becomes more intuitive.
  * A variety of third-party programming systems. By using the PC-based CPU, the options for programming become extremely broad. As with any conventional PC, many third party languages, such as Microsoft®''s Visual Basic® and Visual C++® become options for system control.


• Self-documenting programs. Rather than having to relate the application to the physical I/O addresses of the controller (X000, Y001, etc.), use meaningful text labels, such as "Limit_switch_1", etc. This offers two productivity benefits:
  * Programs are self-documenting. Use device labels that represent the real world system components directly, instead of meaningless controller I/O addresses.
  * Programming work continues independently of electrical design. Advance programming concurrently, not sequentially, while the electrical assignments for each I/O point is being determined. Development time is shortened and costs are reduced.
  * GX Converter, supplied as standard with GX Developer, leverages this further by allowing creation of device name lists offline with Microsoft® Word® or Excel®


• Concurrent development & code reuse. Multiple programs allow the system to be modularized, and specific code written for each part of the machine. Benefits are:
  * Divide development work between programmers, enabling concurrent development and shortened timelines.
  * Reuse code written for a previous application in future applications, saving subsequent project costs. Function block programming eliminates mistakes by dragging and dropping code sections from one project to another.


• Offline simulation. GX Simulator acts as a virtual controller inside your PC, permitting debugging before trying code on actual hardware. Code development can continue before hardware is available, and shop floor disruption is avoided.

More uptime = better bottom line

The benefits carry on past the development stage into maintenance. Q Series will always be operating in a system where other issues can arise. Here''s how it can get you up and running again faster:

• Multiple Programs. Divide machine operation into modular programs and immediately eliminate programs not related to the fault. Hence technicians are led to the fault faster. Modular programs tend to be shorter, so troubleshooting the program concerned can also move more quickly.


• Intelligent Function Utilities. See system configuration and parameters as easy to understand dialog boxes, not hard to read lines of code, allowing a problem to be grasped more quickly.


• GX Explorer. Leverages the transparency of the MELSEC network structure to manage large-scale installations from a single point. GX Explorer''s high-level view of all controllers throughout a plant allows each to be examined both for program and internal data. Hence a technician can arrive at the job site prepared to fix the problem immediately. Since GX Explorer uses remote links to the controllers, their physical location is unimportant. They can be on the other side of the plant or the other side of the world.

Did you know Q Series provides a way to control an endless list of complex high speed motion applications without endless hours of complex engineering?

For motion control, the Q Series Automation Platform is easily configured to support a wide array of applications. By combining the exceptional dedicated motion CPUs with the ease and flexibility of the MT-Developer programming software, system development is reduced to an uncomplicated, time-saving task. Connectivity to Mitsubishi''s digital servos completes a system of unmatched performance and reliability.

Powerful development tools

MT-Developer is the development software for Q-Motion and includes and makes use of Sequential Function Chart program format (SFC), which may be further enhanced by calling the Virtual Programming Language to represent complex motion and mechanical relationships in a graphical manner.

The SFC environment is straightforward and easy to learn, allowing for quick programming, as well as visual identification or diagnosis of motion and sequential event processing. This block-by-block format is further simplified with clear distinctions of motion, arithmetic, and sequence commands. Detailed descriptions and notation capabilities allow for an easy-to-follow program.

The Virtual environment allows a complex machine''s motion requirements to be described using a series of mechanical icons to visually represent gear ratios, transmissions, line-shafts, cam profiles, and more. This type of programming allows for significant amounts of traditional mechanics to be replaced by servo control. Machine size and cost is reduced and program development is simplified.

Cam profiles are created using the development package''s comprehensive software tool. Profiles can be created using predefined standard profiles. Additionally, freeform cam-profiles can be created using spline interpolation. Once the profiles are created, the motion controller has the ability to store multiple profiles and change them on the fly, eliminating the typical downtime associated with mechanical cams.

High-performance CPUs

Dedicated motion CPUs are among the many flexible options of the Q Series'' multi CPU architecture. The 64-bit RISC processors execute high-speed motion tasks independent of other system operations. Direct digital connection to the servos via SSCNET creates a unified network of superior performance dedicated to motion control. CPUs are available in either 8 or 32 axis versions. Up to 96 axes can be controlled from a single Q rack by combining CPUs.

SSCNET dedicated motion network

SSCNET is a high-speed digital interface linking the servo drives to the CPU. SSCNET cycle time is 888 microseconds to the amplifiers, which close their feedback loops locally as fast as 55 microseconds. This configuration not only mates the high performances features of the CPUs with those of the servo drive but also offers many connectivity advantages. Connections are plug-and- play for convenient and time-saving setup. Extensive diagnostics, parameter and data transfer is supported over the network. Items such as position, torque, data registers, alarms, and history are readily available to the user.

World-Class Servos

The MR-J2 Super (MR-J2S) is Mitsubishi''s family of intelligent servo drives and motors. The offering is available in 200 and 400 V models and covers the capacity ranges of 50 W to 55 kW. MR-J2S servos are themselves superior in performance, offering unmatched response and update times, making them ideal for high-speed precision applications. The MR-J2S has an impressive list of standard features, including:

• Advance autotuning to handle changing loads while remaining accurate and stable.


• High-resolution absolute encoders are standard equipment. This is excellent for precision positioning and stability at low speeds. If absolute positioning is needed, just add a battery to the amplifier.


• Extensive diagnosis and load monitoring tools for easy machine setup and troubleshooting.


• Large variety of motors enables a close match to the mechanical design.

The flexible and robust nature of the Q-Series motion controller truly lends itself to an endless list of applications and industries. Targets include automotive, packaging, semiconductor, printing, labeling, food and beverage, and many more.

Did you know Q Series provides a way to implement process control technology without having to pay a process control price?

For many process applications, the DCS has been the preferred way to handle the system. In some large-scale operations, this may continue to be true. However, in many cases, Q Series offers an economical alternative without the cost or complexity of a traditional DCS solution. Key features:

• Performance. Execute multiple process loops, while also processing associated sequence control tasks on the same CPU. Q Series allows a cabinet of single loop controllers to be replaced with a single controller the size of a shoebox. A loop only requires about 400 microseconds to process, insuring high-speed response; 52 different process control instructions give the system designer an extensive toolbox of options for designing a system.


• Uptime. Hot swap capability is supported for the process CPU, and many of the associated I/O modules. System availability continues even when parts need to be taken out of service. Combine this with the outstanding MTBF performance, and you have a system that will offer dependable operation year after year.


• Flexibility. Q Series spans a wide range of process control techniques, such as multiple PID types (velocity, position, blend), PID with 2 degrees of freedom, PID with gap, cascade control, loop tracking, wind-up reset and setpoint generation


• Simplified engineering. Q Series offers an IEC compliant function block programming method for creating the application. Programmers can create the required control scheme by dragging and dropping system elements and using virtual "wiring" to link the different parts of each element. See the separate section on PX Developer below.


• Reduced cost. In some applications, using a Q Series instead of a DCS solution may allow system cost savings of 50% or more.


• Network capability. Q Series integrates with other plant systems via 100Mbit Ethernet, and offers 25Mbit links to other Q Series systems via MELSECNET/H.

PX Developer (Scheduled release late 2004)

The PX Developer process software environment complements the Q Series controller to provide a complete solution for virtually all process control applications. Key features:

• Standardization. Standard IEC function block programming format complies with the expectations of most process control engineers. Standard symbols and nomenclature for process loops, parameter information and other system information, such as FIC, LIC, etc. are offered. Auto-tuning capability removes the trial and error from process setup, while more complex applications can benefit from cascaded loop control.


• Easy to use. All process control functions are represented by PX Developer as a library of graphical objects to drag and drop into place.


• Transparency. Provides a SCADA-like overview of all process loops by representing them as virtual loop controllers. Adjustment of loop parameters is as easy as with a real device.


• Traceability. Trend logging functions allow the response of loops to be examined and adjusted in real time. A full alarm and event monitoring capability is also available.

Sample applications for Q Series process control include:

• Chemical production


• Cooling water control for steel mills


• Continuous sterilization of fruit juice


• Aluminum smelting


• Cement kilns


• Boiler control


• Ion implantation for semiconductor processing


• Building automation


• Waste water treatment

Did you know Q Series provides a way to seamlessly integrate a full-blown PC in a rugged industrial format onto the controller rack?

In some applications, a traditional approach to automation does not work. Many system designers today have no background in the established methods of programming automation systems. Q Series addresses these situations by including a standard, Intel®-based industrial grade personal computer in its lineup of available CPUs. You have the ability to create a completely PC-based control system that uses only the PC CPU and standard controller modules such as I/O. The result is a PC-based control system that loses none of the flexibility of a Q Series platform, while leveraging programming systems such as Microsoft®''s Visual Basic® or Visual C++®. Key features:

• Compactness. Occupies only three slots on standard Q Series rack.


• Integration. Fully integrated into the Q Series platform; included driver software offers a comprehensive library of function calls to allow all Q Series I/O, special function, networking and communication modules to be controlled and accessed from the Q PC. Avoids engineering effort and costs required to integrate a third party PC, software, I/O system, and interfaces.


• Flexibility. Use for control, or as a way to locate a PC right on the controller rack. Avoids engineering issues and costs involved with a separate PC.


• Standardization. Run standard PC-based applications on the controller rack.


• Dependability. Built to the same rugged industrial standards as the rest of the platform; higher resistance to temperature, humidity, mechanical shock, and vibration than a commercial "white box" PC. Maintenance-free design uses no cooling fans, and a silicon disk is available for high vibration environments.


• Interoperability. Full array of connection options:
  * Keyboard, mouse & monitor;
  * 2 PCMCIA slots;
  * 2 USB ports;
  * 2 serial ports;
  * Parallel port;
  * 100Mbit Ethernet;
  * Floppy disk;
  * External hard disk (20Gb supplied).