How To Setup A New S7-1500 Redundant PLC System

In this post, we will see how to set up a new S71500 redundant PLC system, in terms of basic software programming and hardware configuration. Instead of understanding a variety of settings, we will just see the required ones and finish our work quickly. This will help you to program your PLC with all the basic redundancy functionalities. Once completed, you can use both the PLCs as primary and standby, and perform all your software functions smoothly in both of them. 

Which PLC to choose in Siemens for a redundant system?

We will consider the S7-1517H model for our example (H in Siemens PLC refers to high availability models). As seen in the below image, when you create a new project, simply consider this model which has its particular article number. Select that model number and as you can see, two folders named PLC-1 and PLC-2 will automatically be created. 

When you choose a new PLC, the following steps will be asked by the software before the above image appears. This is basically a setup for user password policy and access management. You just need to follow the following steps for easy configuration and starting the project quickly:

1. Protection of confidential PLC data - (password enabled by default, you can disable if not required)

2. Mode for PG/PC and HMI communication - (enabled by default for allowing secure connection)

3. PLC access control - (enabled by default)

4. User management configuration - (by default, use local user management

5. Connection to user management server - (disabled by default)

6. Administrator setup - (nothing by default)

7. Access without authentication - (disabled by default)

8. Access control via access level - (nothing to do by default)

Once done, your new project is now ready to program and download. After that, you need to follow the following steps of images for a quick configuration of the project in terms of hardware:

1. Check PLC firmware and change if required, as actually you see in the PLC.

2. Configure PLC IP address of individual groups (X1, X2, X3) as required for both the PLC’s. For individual groups, if you want to communicate with a device like HMI with PLC, then enable system IP address communication and enter IP address. This is a virtual IP address, which acts as a single bridge for both the PLC’s. So due to this, HMI can communicate with both the PLC’s (when standby becomes primary) immediately, rather than configuring individual PLC IP addresses in the HMI.

3. If you want to communicate in a media ring redundancy protocol with different RIO’s or other devices in the system, then make the PLC as Manager (auto), otherwise keep as not used. For our simplicity, if we have only PLC, then we will not use this option. This option is used when you want to create a ring redundancy in the system with all your IO devices.

4. In security settings, tick anonymous (by default) user for giving full rights in the PLC working. In the assigned roles, tick PLC administrator and PLC F administrator. Not doing this will not compile your program.

With this, your program can now be compiled in terms of both the hardware and software without any error. This completes your program configuration, ready for downloading in the PLC.

Settings to be done in Siemens PLC for redundant system:

Now, the next step is to do some settings in PLC for ease in downloading. First of all, as we have two PLCs, one will be primary and the other as backup. In case of switchover, primary becomes backup and backup becomes primary. Refer to the below image, where P stands for primary and B stands for backup. The primary word which you see in the image, means that this PLC is primary now. When it becomes a backup, it shows backup written. 

 

In the overview menu, we get an option to set redundancy ID. By default, one PLC is set to 1, and the other is set to 2. So, you can check that, and there is no need to change anything. Keep it as it is. In the settings - addresses menu, you can either set the IP address manually or the PLC will assign it automatically once you download. A simple option will be to assign an address manually, so your program connects properly in the first shot before downloading.

Also, connect optical fiber redundant cables between PLC’s for redundancy to function (You will have two cables given). 

How to download PLC program in TIA Portal for redundant system?

Once your above two points are done, your program and hardware is now ready to use. The main thing to note is that you need to click the S7-1500 H folder in the program for downloading, instead of clicking the individual PLC folder in the program. This will ensure that the program downloads in both the PLC’s and they remain always in synchronization. Now, place both the PLC’s in stop mode and download the program. After downloading, place both of them in run mode. 

Once both the PLC’s have come in run mode, your system is now ready to run in redundancy. You can check by either putting primary PLC in stop mode or powering it off. The backup PLC will immediately move to primary mode.

You can refer my video for more details -

I have covered the general theory on setting up a new S7-1500 redundant PLC system in TIA Portal. I have also not attempted to cover all the topics related to it, as it can vary from case to case. Once you are familiar with this type of technology, you can easily troubleshoot any issues related to it.

Thank you for reading the post. I hope you liked it and will find a new way in this type of technology.

Written by Viral Nagda, Industrial Automation Engineer with 12+ years of experience…