– Copied from customer email –
We are currently developing an industrial grade scanner with 3 cameras that need to be connected to a small computer.
The computer has one 2.5 Gb ethernet port. The camera configuration is as follows:
- Cameras 1 and 2:
- Camera 3:
- 1000BASE-T1, Automotive ethernet
I wanted to see if I can use the SPEBlox in conjunction with the Gigabit Switch rugged, to hook the 3 cameras to the single 2.5 Gb ethernet port on the computer.
Also, are the Ethernet connections on the Gigabit Switch capable of PoE? I have put the details of the voltage required in the attached PNG.
I have attached a PNG showing how I would like to wire the 3 cameras using the SPEBlox and the GigaBit Switch.
Yes you can use SPEBlox in conjunction with GigaBlox Rugged as in your diagram. You would need an 8-way picoblade to picoblade cable, which is included with SPEBlox.
GigaBlox Rugged does not have POE capability onboard, but you can add a PoE injector between GigaBlox Rugged and your cameras to achieve this.
You could also look at using POEBlox for the POE, but that is not due for release until March 2024.
Also please note that the 2.5G ethernet port on the PC will only run at 1G maximum. Also bear in mind that you’ll end up with a bottleneck on that port if all three cameras decide to stream at 1Gbps simultaneously.
So if I am understanding you correctly, when I connect the GigaBlox Switch to the Ethernet port on the computer, I will effectively make the max speed of the 2.5G port to 1G. And since I have 3 cameras connected, and if they are streaming at full load, then the total load on the port is 3Gbps but the port will only be capable of handling 1Gbps. Is this correct?
Could you give me your feedback on the systems below?
System 1:
- Does not use PoE
- Cameras 1 and 2 connected to the First 2.5G ethernet, I am assuming this will still create a bottleneck if both cameras run at 1Gbps
- Camera 3 connected to a separate Second 2.5 ethernet port, will this port only run at 1G maximum?
- Camera 3 also powered using the SPE PoE
System 2:
- Uses the PoEBlox card for PoE
- Cameras 1 and 2 connected to the First 2.5G ethernet, I am assuming this will still create a bottleneck if both cameras run at 1Gbps
- Camera 3 connected to a separate Second 2.5 ethernet port, will this port only run at 1G maximum?
- Camera 3 also powered using the SPE PoE
So if I am understanding you correctly, when I connect the GigaBlox Switch to the Ethernet port on the computer, I will effectively make the max speed of the 2.5G port to 1G. And since I have 3 cameras connected, and if they are streaming at full load, then the total load on the port is 3Gbps but the port will only be capable of handling 1Gbps. Is this correct?
In ethernet, two ports will auto-negotiate the highest possible speed that both ports can achieve. This means if you connect a 2.5G port to a 1G port, the 2.5G port will set its speed to 1G so both ports can communicate. This process is called autonegotiation.
If all three cameras decide to stream at 1Gbps simultaneously into a 1Gbps port, then yes, you will have a bottleneck and lose data. It’s highly unlikely that both your cameras would be streaming that much data. For comparison, a 4K video streamed using H.264 encoding needs around 32Mbps, so unless your cameras are streaming some kind of high-def raw format, you’re not likely to see a bottleneck. Check with the camera manufacturer.
If you knew for a fact you’d be having a constant stream of 3 x 1Gbps into a single port, then you’d need to choose a speed for that port that could handle it (for example, a 5Gbps or 10Gbps could handle it).
In system 1:
- Any 2.5G port connected to a 1G port will run at 1Gbps. So all cameras will run at 1Gbps and all ports on your computer will run at 1Gbps.
- SPE PoE is not a very mature technology, there are a few ways of doing it and a lot of hardware is not unified. Our boards no longer support SPE based PoE, so you’ll need to power the camera seperately.
In system 2:
- To use POEBlox to power your device, your device must be compatible with IEEE 802.3af, IEEE 802.3at, IEEE 802.3bt (type 3) or IEEE 802.3bt (type 4). If so, then it will work.
