Introduction

More and more applications and systems for the device monitoring and control focus their requirements on the system safety and maintenance recently. After the entire system is on-lined, when the operating time increases, sometimes the devices may encounter unexpected accident that might cause the system to shut down for several days, or might cause more serious damage to the devices or cause significant disaster. The costs incurred for maintenance and manpower may be very large. In order to avoid such a situation occurs, it's better to design the system as a redundant system (such as: using the Win-GRAF XPAC of ICP DAS) for better safety and easy maintenance in the beginning.

 

Architectures of the Win-GRAF Redundant System

ICP DAS releases a new Win-GRAF PAC series, XP-8xx8-CE6 PAC (Programmable Automation Controller) that meets above requirements in the safety and maintenance for the redundant applications. This document will introduce a number of the most commonly used redundant architectures using the XP-8xx8-CE6, where the architecture (1) to (4) are for the PAC redundancy, and the architecture (5) is a dual redundancy for both the PAC and I/O modules.


Architecture (1): Two PACs without I/O modules



Architecture (2): Two PACs are equipped with DCON I/O modules





Architecture (3): Two PACs are equipped with Modbus TCP I/O modules




Architecture (4): Two PACs are equipped with other Modbus RTU/ASCII I/O modules





Architecture (5): Two PACs are equipped with iDCS-8830 I/O modules (Dual Redundancy for Both PAC and I/O)




 

Features of the Win-GRAF Redundancy

1. Better safety:
There are three communication cables (LAN1, LAN2 and Alive Port) connected between two PACs. The redundant system will still control the process well, even if one or two cables are broken or disconnected. As long as one of the three communication cables is fine, the Win-GRAF redundant PACs can still work well with the process.

2. Unique Public IP:
The Win-GRAF redundant system provides a unique public IP address for SCADA/HMI to access it without needing to determine which one is the Active IP.

3. Easy maintenance:
If one of the redundant PACs is damaged someday after starting the process, you can remove the damaged one, and replace with another spare Win-GRAF PAC or a repaired PAC, and then the healthy PAC will automatically copy the Win-GRAF app and all its redundant data to that new PAC which is just online. It is easier for maintenance and installation, the operator doesn’t have to worry about whether to install the Win-GRAF app or not because the healthy PAC will automatically do it for the new online PAC.

4. Easy to design the application:
The user simply needs to design the application program. Not necessary to specify what data should be redundant between two PACs. The Win-GRAF redundant system will automatically deliver them to the other PAC.

5. Users can design some safety mechanism in the app:
For example, if the Active PAC’s LAN1 is disconnected (causes unable to access SCADA) or a RS-485 Port is disconnected or damaged, and so on. The user’s app can test these events and then switch control right to the other healthy PAC.

6. I/O Redundancy:
If the user chooses iDCS-8830 series I/O, both the PAC and I/O modules can support redundancy.

 

More Win-GRAF Information

More information about the Win-GRAF and XP-8xx8-CE6 PAC Series that supports redundant system can be referred on the Win-GRAF website or the XP-8xx8-CE6 product website of ICP DAS:
Win-GRAF
https://www.icpdas.com/en/product/guide+Software+Development__Tools+Win-GRAF
Win-GRAF > XP-8000-CE6
https://www.icpdas.com/en/product/guide+Software+Development__Tools+Win-GRAF#434