Siemens 505-2571 - Manual (Page 12)

505–2571 Module Description 1-4 SIMATIC 505-2571 Program Port Expander Manual
More sophisticated applications may require the monitoring of a large
number of variables in the controller. There are a number of third party
applications available that may be used to access data from the controller
and perform statistical process control, trending, report generation and
other applications. These third party applications typically run on a PC or
other platform but most all of them communicate to the controller directly
through the program port. Often times there are multiple nodes that need to
be connected to the controller. With the PPX:505-2571 this may easily be
accomplished. See Figure 1-2.
PC Compatible
PPX:505-2571 Module PC Compatible
Figure 1-2 Process Monitoring Application Using PCs