The Siemens Simatic S7-200 is a PLC control unit that offers a variety of functions in multiple industries. The PLCs operate on several different functions and logic operations including counter, timer, OR-NOT, AND-NOT, OR, and AND. Beside the combinational and basic commands, the PLCs have the ability to work with other controllers like PID, mathematical and transfer operations. A standard Simatic S7-200 is designed and built with three major components, which relate to the I/O units, memory, and CPU. The actual command center of the PLC is the CPU which acts like the brain. The S7-200 has the capability to store several types of data in a form similar to binary structure. Also, the range of memory is restricted to retentive , parameter, and program data fields. The function of the I/O units is to help keep communication open between the various different PLC elements.
In case you need to troubleshoot the device, you can do so by checking out the Siemens Simatic S7-200 PDF manual, which can be found under this link: http://sharedf.com/documentation/siemens-simatic-s7-200-user-manual-in-pdf/