Screenshot of Ewon device's web interface

The S5-AS511 IO server allows polling from Siemens S5 PLCs through the PLC’s front programming port using the AS511. A complete list of supported PLCs is available here.

The serial port on the Ewon device must be in RS232 mode.
For the FLA 3301 – 2 Serial Port Extension card:

  • Port S2 is fixed RS232 mode.
  • Port S1 is configurable with dip switches.

Additional configuration may also be required through the web interface in Serial ports.

The Siemens S5 PLC family has a unique memory structure. Data within the PLC are not located at fixed locations within the PLC's memory space.

This memory space is continuously updated and revised as you create and modify your PLC logic.

When these revisions occur, the location of key data elements such as flags, timers, counters, I/O, and data blocks can move around in the PLC's memory.

This IO server has been designed to read the location of these memory elements when the driver first begins operation, upon detecting a communication error, or after a request (which is not a read or a write request) has been transmitted to the PLC.

If you change your PLC configuration you must restart the Siemens S5 IO Server or simply unplug/re-plug the connection cable.

Both actions will cause the Siemens S5 IO server to reacquire the location of all PLC memory elements.

Topic Configuration

Topics give common properties to groups of S5-AS511 tags such as whether polling is enabled or disabled for these tags, their poll rate, and the destination device type and address.

Global Device Address

The Global Device Address is a global parameter that identifies the COM port on the Ewon device connected to the PLC.

Poll rate

Defines the refresh rate of the tag name.

Enter the refresh rate in ms (milliseconds) for the tags associated with this topic. The default value is 2000 ms (2 seconds).

More information about these parameters and the FINS IO server tags can be found in the RG-0007-00 - IO Servers.