Ethernet device with safety features at the physical layer and method for a bi-directional data transfer between two ethernet devices
An ethernet device with safety features at the physical layer and a method for a bi-directional data transfer between two ethernet devices, includes at least one of two ethernet devices with safety features at the physical layer. The ethernet device can switch safety critical traffic from a first ethernet channel to a second ethernet channel if a safety problem has been detected for the first ethernet channel.
1. An ethernet device with safety features at the physical layer, comprising:
a first ethernet physical layer access device comprising:
a first PCS/PMA unit for accessing a first ethernet channel;
a first media independent interface port for ethernet data communication;
a second media independent interface port for ethernet data communication; and
a first media independent interface switch, which in a first operating state connects the first media independent interface port to the PCS/PMA unit and in a second operating state connects the first media independent interface port to the second media independent interface port;
a second ethernet physical layer access device comprising:
a second PCS/PMA unit for accessing a second ethernet channel;
a third media independent interface port for ethernet data communication;
a fourth media independent interface port for ethernet communication; and
a second media independent interface switch, which in a first operating state connects the second PCS/PMA unit to the third media independent interface port and in a second operating state connects the second PCS/PMA unit to the fourth media independent interface port;
wherein the second media independent interface port of the first ethernet physical layer access device is connected to the fourth media independent interface port of the second ethernet physical layer access device;
wherein the first ethernet physical layer access device further comprises a first physical layer safety mechanism unit for detecting a safety problem of the physical layer of the first ethernet channel;
wherein the first physical layer safety mechanism unit is connected to the first media independent interface switch and to the second media independent interface switch for switching the first media independent interface switch and the second media independent interface switch from the first operating states to the second operating states if said safety problem has been detected by the first physical layer safety mechanism unit.
2. The ethernet device with safety features at the physical layer according to claim 1 ,
wherein the second ethernet physical layer access device further comprises a second physical layer safety mechanism unit for detecting a safety problem of the physical layer of the second ethernet channel.
3. The ethernet device with safety features at the physical layer according to claim 1 ,
further comprising a safety controller, wherein the first physical layer safety mechanism unit and/or the second physical layer safety mechanism unit send notifications to the safety controller if safety problems have been detected on the corresponding first ethernet channel and/or second ethernet channel, wherein the safety controller can issue warnings to a system using the ethernet device that the first ethernet channel and/or second ethernet channel has safety problems.
4. The ethernet device with safety features at the physical layer according to claim 1 ,
further comprising a first medium access controller, which is connected to the first media independent interface port of the first ethernet physical layer access device, and a second medium access controller, which is connected to the third media independent interface port of the second ethernet physical layer access device.
5. The ethernet device with safety features at the physical layer according to claim 1 ,
wherein the first physical layer safety mechanism unit and/or the second physical layer safety mechanism unit comprises an input interface for receiving external safety signals.
6. The ethernet device with safety features at the physical layer according to claim 5 ,
wherein the external safety signal originates from the hardware using the ethernet device with safety features at the physical layer.
7. The ethernet device with safety features at the physical layer according to claim 5 ,
wherein the external safety signal refers to supply voltage range violations, temperature range violations, hardware or software built-in self-test results that indicate a component failure during operation, or similar safety critical issues of the external components.
8. The ethernet device with safety features at the physical layer according to claim 1 ,
wherein the first physical layer safety mechanism unit and/or the second physical layer safety mechanism unit detects the loss of the respective link, the degradation of the respective link quality or errors in the received ethernet data packets through link status monitoring through evaluation and/or checking of link idle symbols, through CRC checksum calculation of the received ethernet frames in the physical layer, through error correction codes, through observation of link quality indicators and messaging of degradation of link quality, through echo canceller weight observation to detect cable degradation during operation, through extension of cable diagnostics during operation, and/or through classification of faults.
9. The ethernet device with safety features at the physical layer according to claim 1 ,
wherein the first PCS/PMA unit for accessing the first ethernet channel and/or the second PCS/PMA unit for accessing the second ethernet channel sends a predetermined pattern on the respective ethernet channel if the first physical layer safety mechanism unit and/or the second physical layer safety mechanism unit detects a safety problem for the respective ethernet channel.
10. The ethernet device with safety features at the physical layer according to claim 1 ,
wherein in the first operating state of the first media independent interface switch and of the second media independent interface switch, the first ethernet channel is used for safety critical data traffic and the second ethernet channel is used for non-safety critical data traffic and in the second operating state of the first media independent interface switch and of the second media independent interface switch the non-safety critical data traffic on the second ethernet channel is interrupted and replaced by the safety critical data traffic of the corrupted first ethernet channel.
11. The ethernet device with safety features at the physical layer according to claim 10 ,
wherein in the second operating state the non-safety critical data traffic over the second ethernet channel is immediately interrupted and replaced after a certain threshold by the safety critical data traffic.
12. The ethernet device with safety features at the physical layer according to claim 10 ,
wherein the ethernet device retransmits data traffic that has not been completely transmitted before the first media independent interface switch and the second media independent interface switch have switched from the first operating state to the second operating state.
13. A method for a bi-directional data transfer between two ethernet devices, wherein at least one of the two ethernet devices is an ethernet device with safety features at the physical layer according to claim 1 , comprising the steps of:
providing said first ethernet channel between the two ethernet devices for a bi-directional safety critical data transfer;
providing said second ethernet channel between the two ethernet devices for a bi-directional non-safety critical data transfer;
using the ethernet device with safety features at the physical layer for detecting said safety problem of the physical layer of the first ethernet channel;
if a safety problem of the first ethernet channel has been detected, the ethernet device with safety features at the physical layer switches from said first operating state to said second operating state to:
interrupt the bi-directional non-safety critical data transfer over the second ethernet channel;
re-route the bi-directional safety critical data traffic over the second ethernet channel.
14. The method for a bi-directional data transfer between two ethernet devices according to claim 13 ,
comprising the step of reassembling the safety critical data after re-routing over the second ethernet channel at the physical layer or application of the other ethernet device.
15. The method for a bi-directional data transfer between two ethernet devices according to claim 13 ,
comprising the step of sending a predetermined pattern on the respective ethernet channel for which a safety problem has been detected.
16. The method for a bi-directional data transfer between two ethernet devices according to claim 13 ,
comprising the step of sending a notification to the system using the ethernet device if a safety problem on one of the two ethernet channels has been detected, including if a safety problem has been detected on both ethernet channels.
17. The method for a bi-directional data transfer between two ethernet devices according to claim 13 ,
comprising the step of receiving an external safety signal regarding the first ethernet channel and/or the second ethernet channel.
18. The method for a bi-directional data transfer between two ethernet devices according to claim 17 ,
wherein the external safety signal originates from the hardware using the ethernet device with safety features at the physical layer.
19. The method for a bi-directional data transfer between two ethernet devices according to claim 17 ,
wherein the external safety signal refers to supply voltage range violations, temperature range violations, hardware or software built-in self-test results that indicate a component failure during operation, or safety critical issues of the external components.
20. The method for a bi-directional data transfer between two ethernet devices according to claim 13 ,
wherein in the second operating state the second ethernet channel is immediately interrupted and replaced after a certain threshold by the safety critical data traffic.
21. The method for a bi-directional data transfer between two ethernet devices according to claim 13 ,
comprising the step of retransmitting data traffic that has not been transmitted before the switch from the first operating state to the second operating state.