At Bernecker Rollforming & Tubes - as with many other users - it is mainly S7 CPUs that control the machine park. The company, which has four locations in Europe, is a system supplier in the automotive sector. The scope of services ranges from consulting, development, design and tool creation to the production of parts or complete assemblies. Complex forming technologies and various joining processes form the focus of production. At the Vogtland site in Pausa, the company manufactures roll-formed products such as tubes and stamped parts for the automotive industry.

In addition to the S7 CPUs from Siemens, S7 CPUs and S7 panels from Insevis have also been added over time. The equipment engineering department, headed by Peter Klamuth, was now given the task of visualizing existing S7 applications cost-effectively to improve system support. Experience with the easy-to-configure S7 panels from Insevis provided a starting point, especially as the existing Simatic Manager was to continue to be used for S7 programming in the plant in order to keep license costs low. The S7 PLCs from Insevis accept S7 programming via Simatic Manager and TIA Portal.

Based on the existing visualization on the existing panels, Peter Klamuth and his colleagues took a completely new approach: they created a binary file from the existing visualization of a vertical 10-inch installation panel and copied it to a standard Windows tablet. From this, the remote stage software running there generates the visualization and links the Windows tablet directly to the S7 CPU via WLAN. After identifying the S7 CPU via IP address and TSAP, active S7 communication (put/get, send/receive) was established, which transfers process data to the remote visualization. This created an additional mobile visualization.

With this approach, the automotive supplier was able to use a new technology without breaking the budget for equipment construction or having to introduce new software tools.

The necessary steps

Figure 1: The first step is to define the size of the visualization, as shown here for any PC screen with free scaling.

© Insevis

Below are the individual steps for creating the free visualization for S7 CPUs with Ethernet for S7 communication described. The required visualization software is called Visu-Stage at Insevis and is available completely license-free in one project language or with a mini company license for all languages in the world. The number of installations/workstations is generally unlimited. With the easy-to-use software, WinCC-flexible users find their way around relatively quickly, even for non-experts. This includes, for example, a comprehensive fault message system with 1024 alarms, 1024 events, 64 trend channels, nine user levels, 64 recipes each with 256 data records from 256 elements, an unlimited number of I/O and time/date fields, round displays, bar graphs, sliders, text and image lists.

Limitations due to power tags or runtime licenses have been completely dispensed with in favour of the user. The operation of this software is simple and documented in German and English manuals with reference to downloadable sample visualizations.

After selecting the desired size for the visualization interface (see Fig. 1), the visualization is created in the usual way. S7 variables including symbols can be imported from the Simatic Manager or TIA project. Existing .emf and .wmf images from WinCC and WinCCflexible can also be imported, including transparency. Once project planning is complete, users can use the integrated simulator to manually stimulate the effect of changed process values in order to check the result in the visualization. A meaningful error report helps with debugging until the visualization is error-free. If everything runs correctly, the visualization is compiled into a binary file.

Integration of S7 CPUs

Figure 2: The user defines the target CPU via the IP address and TSAP.

© Insevis

This binary file would normally be loaded into the Insevis S7 panels to be executed by the operating system. For the planned use on a PC and with third-party CPUs, however, the procedure is different and the second free Insevis software 'Remote-Stage' helps. This command line tool runs on Windows XP/7/10 and includes a driver for S7 communication with Siemens CPUs. The target CPU is identified by IP address and TSAP and connected via Ethernet (see Figure 2). Then the visualization binary file previously created with the Visu-Stage software is opened and remotely simulated with the process data of the S7 CPU to a second (third ..., n-th) screen. The remote page switches are separate from those of a possible panel on the local CPU and do not affect the operator there. However, the process data can be changed remotely. If you want to have a free 1:1 image of the panel, you should use the integrated VNC server for the Insevis S7 panels and display the 1:1 counterpart with the Sm@rtClient from Siemens or other VNC clients.

Archiving of messages and trends

A second instance of the remote stage software is used to display and save the archives that are created in the PC's system memory during the remote connection and can be saved in csv format. As the software is a command line tool, it can also be called automatically with the Windows task scheduler, which can be parameterized step by step, and archiving can be executed (with a few call parameters).

This makes it possible, for example, to store all channels of a trend in a specific network drive as a csv file at a defined point in time. The remote stage is multi-instance capable, i.e. it can be called up several times. This opens up the possibility of creating a free control room function for the remote display of several PLCs in several windows on a remote screen. Insevis customers who have been using the software to visualize their entire Siemens CPUs for some time have had very good experiences with it - for example with inexpensive Windows tablets running the software - replacing expensive mobile panels.

Others use Remote-Stage on a small box PC and use a large-format LED TV as a large-screen display. If you are open to new approaches, you can create impressive visualizations with minimal effort.

1:1 visualizations via VNC

Figure 3: There are various ways to implement free remote visualization.

© Insevis

If you want a 'mirrored' remote screen, you can use a VNC client, whereby the screen content is provided by a VNC server. This is already included as standard with most S7 panels and S7 panel PLCs from Insevis and can be set up during the creation of the visualization with the Visu-Stage software.

The devices mentioned represent the actual product portfolio of the S7 system provider Insevis, which are at home as S7 alternatives or extensions in countless price-sensitive S7 applications. The devices can be programmed with the Simatic Manager 5.5 or with the TIA Portal V13/14 (in IL, LD, FBD, S7-SCL, S7-Graph) with virtually the command scope of an S7-315-2PNDP and with 2 MB RAM. The basic version of every S7-CPU from Insevis already has Ethernet (TCP, UDP, S7 communication), Modbus (TCP and RTU), CAN (CANopen and Layer2) and a serial CP with RS232 and RS485 (free ASCII). The newer PLCs even include two separately configurable Ethernet connections (for customer IT and own service access). This alone enables use as an S7-programmable fieldbus gateway. The CPUs can also be equipped with Profibus DP master/slave or with Profinet I/O controllers. The SFCs and SFBs required for this are available free of charge on the Internet, along with sample applications and demo videos on their handling.

In this way, Insevis enables every user to generate great additional benefits in a wide variety of ways completely free of charge in addition to their own hardware. This can save costs, especially for equipment manufacturers.

Author:
Jörg Peters is Managing Director of Insevis.