PROFIBUS Support – Success Story POSCO Steel
By UL Group
POSCO, leading steel producer in the world relies on UL Group for PROFIBUS Diagnosis Services to keep their PROFIBUS network running 24x7.
POSCO has strong presence in India. To provide value added steel processing services to auto customers, they have total 4 state of art facilities in Delhi, Pune, Hyderabad, and Chennai.
One of the largest steel producers in the world POSCO predominantly rests their faith in PROFIBUS as their preferred networking fieldbus resonating with virtually the whole steel sector worldwide, thanks to reliability and determinism which PROFIBUS technology demonstrated for decades in harsh environments of sectors like steel industry and dire consequences associated with down time.
It was heartening to get a call at 5 AM from Managing Director of prestigious corporate like POSCO. To some extent it pampers the service person about his importance but is also challenging situation since it is also the test of your experience and expertise at once and the stakes involved are high, there is no choice to fail. In such a situation, the moral boosting aspects of a PROFIBUS engineer are: PROFIBUS itself and UL’s rich experience of decades to back up.
The vehicle to collect me was at my door at 9 AM, reached plant at 1 PM and network was running without any concerns at 2 PM. What a relief!
What was the problem?
POSCO was continuously facing PROFIBUS node failure in PMS CGL AIR KNIFE network. Because of this issue they were facing production loss.
EXISTING PMS CGL AIR KNIFE PROFIBUS NETWORK
Action taken by UL to solve this problem
1. First I understand customer complete PROFIBUS network and their problems which they were facing. Also I try to understand whatever action POSCO was taken to solve this issue.
2. After understanding customer issues I generated PROFIBUS diagnosis report for existing network without implementing any changes in the network. For this health check-up I used Procentec ProfiTrace Ultra Tool.
3. Form that report I found some termination and cabling issues in the network.
Pic-01: AB differential voltage at 1st stage without doing in modification in the network
4. Then I started checking termination one by one from 1st PROFIBUS node to last node.
Where I observed that at starting node on Master termination is in OFF state which is wrong. So I set it as ON.
After this change once again I checked PROFIBUS network heath and I got some improvement in voltage level but this improvement was not up-to the mark.
5. After above change I went towards repeater where POSCO already done some work.
6. At repeater I found wrong cabling was done. To make it as correct I done below changes at repeater end.
- 1st connect A and B line properly which earlier wrongly connected.
- 2nd interchange PROFIBUS segment from A1’-B1’ to A2-B2 to effectively utilized repeater functionality.
7. After all these modification once again I checked PROFIBUS network by using Procentec Proficore Ultra Tool and at this time I received result up to the mark.
8. I also cross-verified same point in PLC and keep system under observation for almost 4 hrs and within 4 hrs I not received any compliant from customer.
9. Finally I generate PROFIBUS diagnosis report with all implemented modification and handover system to customer in healthy-running condition.
Pic-02: AB differential voltage after implementing changes in the network
MODIFIED PMS CGL AIR KNIFE PROFIBUS NETWORK