Remarks on the measurement principle

To measure SIMATIC TDC system numeric values must be transported between the

TDC system and the PC, which means that internal variables of the TDC system may

be visualized and recorded. For recording purposes two different software packages

are provided by iba.

Request-TDC (former name Symbolic Request):

The definition of the signals to be measured is independent of the connected system.

All changes are done in ibaPDA. ibaPDA supports the functionality to select the internal

TDC variables by their names, i.e. the plan, function block and the connector names.

To do that for every TDC CPU 2 service function blocks must be included in the CFC

plan of the TDC system. These function blocks support also overload protection to

avoid high system loads by ibaPDA.

The information about the variable names (address book) is not provided by the TDC

engineering software, but is transferred from the TDC CPU to the ibaPDA system di

rectly via the ibaFOB-TDC card.