Efficient Networks S120 manual Set RT class, Profinet IO with RT, Not isochronous, Data exchange

	Communication PROFIBUS DP/PROFINET IO
	10.3 Communications via PROFINET IO
RT class	RT	IRTtop
Maximum switching depth (number of	10 at 1 ms	20
switches in one line)
Synchronization accuracy	-	Forwarding of the sync message frame
		in software.
		Accuracy <1 µs
Possible transmission cycle clocks	500 (as of FW2.5 SP1), 1,000, 2,000,	500 (as of FW2.5 SP1), 1,000 – 4,000
(observe any device-specific	4,000 µs	µs in increments of 125 µs. The
restrictions)		increment depends on the controller.

Set RT class

The IO controller determines which RT class its IO system supports, by setting the real time class at its controller interface. If IRTtop is set, it is not possible to operate any IRTflex devices on the IO controller and conversely. RT devices can always be operated, even if IRT classes are set.

You can set the RT class in the HW Config for the associated PROFINET device.

1.Double-click on the PROFINET board entry in the module in HW Config. The "Properties" dialog box is opened.

2.Select the realtime class for RT class in the Synchronization tab.

3.Confirm with "OK".

10.3.3.2PROFINET IO with RT

PROFINET IO with RT is the optimal solution for the integration of I/O systems without particular requirements in terms of performance and isochronous mode. This is a solution that also uses standard Ethernet in the devices and commercially available industrial switches as infrastructure components. A special hardware support is not required.

Not isochronous

Because standard Ethernet does not support any synchronization mechanisms, isochronous operation is not possible with PROFINET IO with RT!

The realtime capability is comparable with the present PROFIBUS DP solutions with 12 MBaud, whereby a sufficiently large bandwidth portion is available for the parallel transmission of IT services on the same line.

PROFINET IO message frames have priority over IT message frames in accordance with IEEE802.1q. This ensures the required determinism in the automation technology.

Data exchange

Communication is possibly only within a network (subnet).

Drive Functions	445
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4