SIL3 Network Switch
Any one has any idea on Network Switches which is SIL3 certified ?
or any SIL certified Switches in market.............
As far as I understand, SIL classification does not include Ethernet communication (or more precise, how the transport of an Ethernet telegram is taken care of)
All SIL applications running in AC 800M calculates checksums on the telegram exchange made over Ethernet to be able to detect and react on bit errors and losses. This check is independent of the transport & physical layer of Ethernet.
ABB has certified a number of different vendors of Ethernet equipment for use with System 800xA, please refer to this link on ABB external web: http://new.abb.com/control-systems/system-800xa/800xa-dcs/system/certified-3rd-
Safety standard allows two design approach. black channel and white channel. In white channel approach, entire communications channel including its interfaces complies with the requirements of IEC 61508. In black channel approach, there is no available evidence of design or validation according to IEC 61508 standard. However, data (and connected elements) must have built-in mechanisms to detect any interference and with a confidence level of detection that is suitable for the safety application relying on the data.
ABB has followed black channel approach, wherein safety header & CRC is inserted in telegram, to detect corruption, reptition, incorrect sequence, delay, insertion etc...
Therefore, you shall follow the recommendation from safety supplier about it. In case, of ABB, you may consider approved switches as per IIT certified hardware portal.
I could find one manufacturer, which has SIL-2 switch.