Diagnostic of Fault-tolerant System S7-400H

In a standard technical or PLC programmer praxis we meet in our daily with an obligation to know to diagnose control processing units CPUs, industrial network or devices which are connected to the CPU. We can remove failures very quickly in dependence on the right fault recognition. There is a lot of industrial applications which are required continuous production. Stop such production can means large material claims. In a worse occurrence it means risk to person. Because of these, we choose control system SIMATIC S7-400H as a system, which we will monitor. These control systems are used for more difficult and demanding industrial solutions, where requires on a redundancy exist. This article provides you information about using of system and standard blocks in the operating system of CPU for SIMATIC S7-400H. We will show one way how to read out diagnostic datas from CPU through SZL function. We will use WinCC flexible for simply results visualization.