User manual

20-4
PC-based Controllers & I/O Modules
APAX System Architecture
Application Ready High Performance
PACs
Advantech’s APAX-5570/5571/6571 series offers several high performance controllers
with Atom and Celeron M grade CPUs. These controllers benefit from the high throughput,
openness, flexibility and connectivity brought by PC-based architectures. Contributed
by excellent heat dissipation technology with no hard disks, they deliver great system
reliability. Various peripheral interfaces such as LAN, USB, DVI, audio, RS-232, RS-
422/485, etc, are provided. These high performance PAC controllers are suitable for
many complex control applications.
Introduction
To simplify the system configuration, Advantech’s APAX-5000 series provides an easy and flexible way to setup different functions and configurations. There are multiple APAX series
system combinations that can be selected to develop reliable control systems as detailed below.
Robust, Compact PACs
APAX-5520/5620 series controllers offer a compact size without fans. These controllers
have no rotating parts, helping further increase system reliability. APAX-5520/5620
features a VGA interface, enabling local displays, and its RS-485 and LAN ports offer
communication ability with Modbus protocol. Internal CF slot and battery backup RAM
can be used for data storage. These features make APAX-5520/5620 as compact and
robust as a PLC, but with enhanced displays, connectivity, and storage.
Scalable Systems with Remote I/O
For different fieldbus or real-time Ethernet networks, such as Modbus, Ethernet/IP, Profinet,
etc, APAX series offers different kinds of couplers for communication. Any controller or
computer in the same network can access APAX I/O modules through the coupler. Not
having to change I/O modules for different fieldbus or real-time Ethernet networks helps
ensuring current I/O modules’ investment for future demands. These couplers feature
daisy-chain design, making installation easier.
Reliable Control System with Backup
Technology
APAX-5000 series delivers system backup functionality to significantly decrease the risk that
the system will fail when the controller crashes. To leverage this, two controllers with the same
control program are installed in one system. After both controllers’ backup functions are enabled,
APAX-5000 will automatically delegate one controller as the master controller.
The master controller will run the control program to execute the control process, while
another controller (the backup controller) is put on standby. The master controller
periodically sends live messages to the backup controller. If the backup controller does
not receive a message from the master controller, it will automatically become the master
controller and restart the control process.
If the master controller is switched, it means there was an error happening on the previous
master controller. Therefore, engineers can repair or change the previous master controller
and re-enable it as the backup controller. Then if the new master controller fails, the new
backup controller will automatically take over the control once again. This mechanism
ensures the control system will continuously run the control process.
Unique and Dedicated System with
Dual Controllers
APAX-5000 series features a unique system architecture, two individual controllers
executing different tasks, integrated into one platform. One controller focuses on I/O
control processing while the other controller possesses high computing performance to
be responsible for tasks like database, HMI/SCADA software, recipes, communication,
storage, vision processing, and more.
For example, APAX-5570XPE can be one controller delivering powerful computing ability
and sufficient resources to execute all other tasks except I/O processing. Another controller
could be APAX-5520KW, concentrating on I/O control. For many control applications,
I/O control is critical, and this dual controller architecture offers excellent reliability and
efficiency. Regardless of what happens on the APAX-5570XPE (even if the operating
system crashes), I/O control process is still secure.
Any application running on APAX-5570XPE, such as HMI/SCADA software, can access
data from APAX-5520KW through Modbus protocol. HMI/SCADA software that supports
Modbus clients can link to Modbus servers on APAX-5520KW to get data. Advantech
offers related libraries for programmers. This can significantly save a lot of development
time for communication.