Key Technical Specifications
| Parameter | Specification |
|---|---|
| Data Rate | 2Gb/s (2.5Gbps max) |
| Port Count | 8x SFP Optical Ports |
| Node Capacity | Up to 256 nodes (cascadable) |
| Max Link Distance | 10 km (Single-mode SFP dependent) |
| Management Interfaces | RS232 Local, 10BaseT Ethernet Remote |
| Fault Tolerance | Auto-bypass on signal loss/sync loss (<50ms) |
| Form Factor | 19-inch 1U Rackmount or Desktop |
| Power Supply | Internal Universal AC |
| Signal Regeneration | Serial optical signal regeneration per port |
| Dark-on-Dark | Supported (Firmware v02.00+) |
Product Introduction
When a single node in a real-time reflective memory network dies, the whole ring can go down. I’ve seen entire test stands halt because of one bad transceiver. The GE ACC-5595-208 exists to stop that bleeding. It acts as a managed optical hub for the VMIC 5565 series, taking in serial optical signals, regenerating them to kill jitter and cable loss, and routing them to the next node. If a port drops sync or loses light, this hub isolates it in under 50ms. The rest of the network keeps running without missing a beat.Engineers stick with the 350-805595-208N because it actually delivers deterministic latency. You get predictable data sync times around 2.1μs, which matters when you are coordinating motion control or running real-time simulations. It takes standard SFPs, so you can mix short-reach multimode for the lab and single-mode for long runs without buying different hubs. Fair warning: this specific revision is incredibly sensitive to dirty fiber end-faces. Clean your connectors before plugging in, or the auto-bypass will keep tripping and you’ll waste hours chasing ghosts.
Quality SOP & Tech Pitfalls
I don’t trust a hub until I’ve tortured it on my bench. Every ACC-5595-208 gets a visual inspection under magnification to check for cracked SFP cages or corroded pins. I plug it into a live test rack and push 2Gb/s traffic through all eight ports simultaneously for four hours. I use a Fluke multimeter to verify the internal universal power supply is holding steady under load. Firmware version gets logged, and if it’s below v02.00, I flag it for the dark-on-dark limitation. Finally, it goes into an anti-static bag with foam corner protectors.Here is where guys mess up: they swap this hub and forget to check the DIP switches or firmware. I once took over a site where the network kept dropping every 20 minutes. Turns out the new hub had an older firmware that didn’t handle the dark-on-dark feature right, and the auto-bypass was stuck in a loop. Another classic trap is mixing SFP types without checking the link budget. Shoving a 10km single-mode optic into a 2-meter multimode run will fry the receiver. Always photograph the old hub’s configuration before pulling it.
Installation & Configuration Guide
- Pre-Installation: ⚠️ Power down the entire reflective memory ring. Wait 60 seconds for capacitors to discharge. Take clear photos of the existing SFP layout, fiber routing, and any DIP switch positions.
- Removal: Label every fiber cable with its corresponding port number. Release the DIN clips or rack screws carefully. Pull the old hub straight out to avoid bending the backplane pins.
- Installation: Copy all DIP switch and jumper settings from the old hub to the new ACC-5595-208 exactly. This prevents 90% of startup communication failures. Seat the new hub firmly and secure the mounting hardware.
- Power-On & Testing: Apply power and watch the LED boot sequence. Verify 24V/5V internal rails if accessible. Check the RS232 or Ethernet management port to confirm all 8 ports report valid sync. Download any required configuration files and verify end-to-end latency.
Compatible Replacement Models
| Model | Compatibility Tier | Notes |
|---|---|---|
| ACC-5595-208 | ✅ Drop-in Replacement | Exact hardware match. Verify firmware matches your existing ring. |
| 350-805595-208N | ✅ Drop-in Replacement | Alternate OEM part number. Functionally identical to ACC-5595-208. |
| ACC-5595-208 (Rev B) | ⚠️ Software Compatible | Hardware identical, but requires firmware alignment. Expect 1 hour labor for flash/config. |
| ACC-5595-210 | ❌ Hardware Mod Required | Different port count/backplane. Requires rewiring and chassis modification. Do not use as a direct swap. |
Frequently Asked Questions (FAQ)
Can I hot-swap this hub while the network is running?
No. Pulling a managed hub out of a live reflective memory ring will break the optical path. Even with auto-bypass, the transient will cause a network fault. Schedule a maintenance window and power down the segment.Why does my new hub keep bypassing ports randomly?
Nine times out of ten, it’s dirty fiber. Reflective memory runs at 2Gb/s. A single speck of dust on the SFP face will cause intermittent signal loss, triggering the auto-bypass. Clean the end-faces with a one-click fiber cleaner and re-test.Do I need to populate all 8 SFP ports?
No. The hub only regenerates signals on ports with an installed and active transceiver. Leave empty ports alone. Just make sure you don’t accidentally leave a broken SFP plugged in, as it can confuse the management logic.Can I mix multimode and single-mode SFPs on the same hub?
Yes, that is actually one of the best features of this hub. You can run multimode for short lab links and single-mode for long-distance connections. Just verify your link budgets match the SFP specs.Is the Ethernet management port mandatory?
No. The RS232 port handles local config and monitoring. The 10BaseT Ethernet port is just for remote access over TCP/IP. If your cabinet is locked and you have laptop access, RS232 works perfectly fine.What happens if I lose power to the hub?
The optical ring will break, and nodes on either side of the hub will lose sync. When power returns, the hub boots up and re-establishes the links. Plan for a brief network interruption during power recovery.Does this hub support 10GbE SFP+ modules?
No. It is strictly a 2Gb/s (up to 2.5Gbps) platform. Plugging in a 10G SFP+ module will result in a link failure. Stick to 1G/2G SFPs rated for this data rate.
