Siemens SIMATIC ET 200M

Technical Specifications
10.4 Technical specifications of the IM 153-4 PN interface module
ET 200M
Operating Instructions, 12/2008, EWA-4NEB780600602-08
235
Isochronous real-time communication
Synchronized transmission method for the cyclic exchange of IRT data between PROFINET
devices.
A reserved bandwidth is available within the send cycle for IRT IO data. The reserved
bandwidth ensures that IRT data can be transferred at reserved synchronized intervals,
without being influence by other higher network loads (e.g. TCP/P communication, or
additional real-time communication).
The "high flexibility" IRT option enables the best possible flexibility. It is not necessary to
configure the topology.
For further information please refer to the STEP 7 Online Help and the "PROFINET System
Description (http://support.automation.siemens.com/WW/view/en/19292127
)" manual.
Prioritized startup
Prioritized startup denotes PROFINET functionality for accelerating the startup of IO devices
for RT and IRT communication within a PROFINET IO system.
The function reduces the time that the correspondingly configured IO devices require to
recover the cyclic exchange of user data in the following situations:
● after power has returned
● after station recovery
● after activation of IO devices
Note
Ramp-up time depends on the number and type of modules. Also note that the minimum
ramp-up time increases by 1.5 seconds if you are using the active backplane bus.
For further information please refer to the STEP 7 Online Help and the "PROFINET System
Description (http://support.automation.siemens.com/WW/view/en/19292127
)" manual.
Device replacement without removable media / programming device
IO devices having this function can be replaced easily:
● You do not require any removable storage medium (for example, SIMATIC Micro Memory
Card) with saved device names.
● The device name does not have to be assigned using the programming device.
Instead of being assigned a device name from the removable medium or programming
device, the IO device is now assigned a device name by the IO controller. The IO controller
uses the configured topology and the correlations derived from the IO devices. The
configured target topology must agree with the actual topology.
For further information please refer to the STEP 7 Online Help and the "PROFINET System
Description (http://support.automation.siemens.com/WW/view/en/19292127
)" manual.