Reviewer details
Name: Donald Pittendrigh
Position/Designation: Owner
Company: I-ASICC
Telephone: 083 644 9556
E-mail: [email protected]
Product details
Vendor: Siemens
Product name and version: WinCC V6
Telephone: 011 652 2000
E-mail: [email protected]
URL: www.iasicc.co.za
General
Q: What industry (eg, mining, food and beverage, automotive etc) is the scada being applied in?
A: Chemical
Q: Describe the application briefly giving a description of any existing control systems, any previous scada system that was in place etc. If relevant, describe the switchover from the previous system?
A: The previous system was a distributed control system consisting of Siemens 115U PLCs, Mitsubishi PLCs and Conet remote I/O stations. The system has been upgraded to Siemens S7400 with ET200M remote I/O stations at each machine. Each machine in the factory is also equipped with a visionbank thin client running the scada application on terminal services on a centralised Windows 2003 server equipped with WinCC V6 and Web navigator.
Q: Who did the system integration?
A: Donald Pittendrigh I-ASICC
Q: Approximately how many man-hours did the integration take?
A: Approximately 500 hrs and the current project phase is 85-90% complete.
Q: How is the after-sales support handled (eg, remote-dial-up, e-mail, Internet access etc)?
A: The plant is local and the client calls the SI to site directly. This will continue until commissioning of phase 1 is complete. Microwave link to the SI offices and clients' engineering manager is planned for future phase of expansion.
Q: What sort of licensing agreement is used on this particular system? Does one licence cover all modules, or can the user only buy those modules that he wishes to use?
A: The system was supplied complete by the SI. The control system package essentially comprises five licences, one for the basic scada, one multi-user licence for the terminal services clients, one for ProAgent advanced diagnostics, one for the Step 7 programming package and one for the HiGraph sequence control.
System architecture
Q: How many tag points/I/O does the installation have? Analog? Digital? Maximum possible?
A: 5500 used tags/2176 analog/3324 digital/64K possible. Final tag utilisation can be expected to reach 20-30K.
Q: What operating system is the scada running on (eg, Windows NT, Unix etc)?
A: Windows 2003 server.
Q: What impressed you most about the architecture? Open standards, wide range of drivers, the ability to upgrade, etc? Please elaborate.
A: The interaction with the Siemens programming package, what Siemens calls TIA, significantly shortens the engineering time and improves accuracy on tag generation and alarm text message generation. A symbol created in the PLC program automatically becomes a tag without setting up and testing of the new tag. It cannot be created incorrectly or from the wrong address unless the mistake was already created in the PLC program. The creating of tags from structured tags makes the editing and creation of the database for multiple repetitive tags very simple and quick to do with 100% accuracy and thus commissioning time significantly shortened.
Q: Is the system integrated onto an intranet or the Internet? If so, does the configuration allow simple remote monitoring, or is it configured to allow full remote control? If not, what level of intranet/Internet control does the scada allow for future use?
A: The system uses terminal services to control the plant via remote thin client devices, this happens over an intranet created for this purpose and could be extended to the Internet at will and with ease. The selective authorisation of control enabled or disabled for a particular log on ID makes it safe to access the control system via the public Internet provided the appropriate windows security is in place. This is visualised as a future enhancement.
All existing terminal server nodes have full control capability; view clients may be created in management offices as a future enhancement.
Q: What sort of redundancy is built into the system?
A: No redundancy is currently in place, redundant servers for the scada are planned for the next phase of expansion, the current project is not mission critical but will become so after the next expansion and upgrade. The system installed has the capacity to accommodate redundant servers and design has been done with this feature in mind.
Graphics
Q: Describe the graphics development process - eg, did you use standard library images, or did you have to draw images from scratch?
A: Most of the graphics items are created from the standard library; only pushbutton local station faceplates were constructed from custom drawn items.
Q: How would you describe the library of graphic images?
A: Boundless, far more available than we could ever use.
Q: Did you use any 'special' images (eg, embedded video clips, photographs, 3D images etc)?
A: No - this is not planned for the future either.
Compatibility
Q: Did you run the scada in conjunction with any third-party application software? Describe.
A: No, none was needed, but future gateway to SAP is envisaged.
Q: Does the scada allow for the user to create scripts to perform specific tasks? Describe any specific scripts that were written for this project.
A: The scada caters for visual basic and C scripting, scripting was only used at the lowest level for pushbutton control of switching several picture items on and off simultaneously. Further the use of scripting was avoided and found in the main to be unnecessary as the standard WinCC tools provide adequate flexibility.
Management reporting
Q: Is a trending and historical data reporting system included? Please elaborate.
A: Live trend pictures for recording of online tags are used for high speed trending to tune PID loops. All analog signals are trended historically with a resolution on 750 ms and the archive goes back for at least one week. Larger historical archives are not currently required. Historical trend views are broken into four trend groups to simplify selection of the desired analog signal when viewing trends.
Q: Is a management reporting system included in the package?
A: Not at present but visualised for the future, the package does have reporting capability.
Q: Is the system integrated into a manufacturing execution system?
A: No, the client has no such system at this stage.
Q: Is the scada system integrated into a management reporting or control system (eg, SAP, Baan)?
A: SAP gateway is visualised for next year's expansion project.
Q: Who integrated the scada into the MES and/or ERP?
A: N/A.
Q: Describe the integration process.
A: N/A.
Q: Was any additional software development needed? Please elaborate.
A: N/A.
Conclusion
Q: What impressed you the most about the system?
A: Implementation of the Siemens TIA concept and the efficiency achieved by integration into the Step 7 PLC programming package.
Q: What was the predominant feature (or features) that made you decide to employ this scada, rather than another (ie, ease of use, support from the vendor, upgrade path, redundancy features etc)?
A: The client was looking for a single vendor solution and found that the only available system supplying PLC control and scada that suited his specification was Simatic TIA.
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