The tech-support department here at Creative Conners occasionally gets calls about connection problems between Spikemark and the Stagehand. Recently, we heard from a customer running a show with 19 axes and they were having 3-4 network failures per show. We got their log and show files and started looking into how Spikemark was handling the demands of the show, the firmware in their Stagehands and the quality of their network hardware. Gareth headed out to check out the situation himself and after a solid look-through of the whole setup, they decided that a good first step was to replace all of the ethernet cables with brand-new cables. The problems went away, and they ran the last week of their show without a single network connection issue.
Through all of this, we learned a few new things about network communications, confirmed some existing assumptions and found an awesome new tool, so we decided a blog post was in order to share what we know.
The first step of diagnosing and fixing network issues is to look at the quality of the cable. We found a great tool for this, the Fluke Networks MicroScanner 2. You just plug your ethernet into the tester and it will tell you the length of the cable (surprisingly handy!), whether there are any faults in the cable, and whether the cable is properly installed. In last week’s problem, the cables were made in the theatre’s scene shop, and were replaced by molded, shielded cable. With the cables that were bad, the only problem was the physical connection at the connector, and these faults were all caught right away with the MicroScanner, so we’re pretty excited to have that tool in our tool box. Here’s picture of the MicroScanner at work:
Another problem we look for in cables is electrical interference. The less expensive cables are not shielded, but shielding can help remove another possible culprit, especially if your cables are running in bundles with power cables, and as a bonus, the shielding makes the cables a bit more robust, which can extend their lifespan. However, if you use shielded cables you need to use a shielded network switch also (more on that later). Our recommendation is to purchase nice, shielded cables and replace them as necessary.
Switches are the next piece of the puzzle to look into. For a basic switch, we recommend this one from Cisco, and it’s the one we include with our kits. Most switches in this price range are not shielded, so if you’re going shielded, this one is a good choice, or if you’re installing the switch in your own enclosure, this one from Phoenix Contact is a good choice. Please note that both of these switches need to be grounded in order for the shielding to be effective. If you’ve already got a switch, and you’re trying to figure out if it’s shielded, look for a metal grounding strip on the inside walls of the jacks:
Another point about switches is the data transfer speed specification. The maximum data speed on our Stagehands is 10Mb, so if you’re looking for switches and you see a spec like 1Gb, that’s great but you won’t be able to leverage that speed with your automation, so it’s better to spend the money on shielding or more robust connections (like EtherCon).
If you want to take your network communication to the next level, we recommend EtherCON connectors for your cables, which we ship with our kits. These are XLR-type hoods that mount over the ethernet connector on the cable and click into an EtherCON connector on your switch or any of our Stagehands. It’s very robust and a positive lock. The connectors are very affordable, so it’s a great first step for improving your setup. If you’re looking for pre-made EtherCON cables, try Lex Products. A great part about the EtherCON connectors is that you can purchase them and apply them on top of your existing cable. Just make sure you have non-booted Ethernet cables, since the strain relief of the EtherCON shell replaces the boot. Here’s what the EtherCON looks like on the face of our Stagehand:
Finally, if you want the best of the best, we recommend the Chroma-Q Magic BoxTM EtherSwitch 7. This switch has a metal rack-mountable enclosure, shielded operation, and it’s made for the entertainment industry. It also comes with a captured-nut mount on top for Mega-Clamp mounting to your truss or pipe. It’s widely used by the lighting industry, and all the qualities that make it a go-to product for those guys make it the best switch for your automation.
That’s a lot, but please let us know if you have anything to add from your experiences or if you have any questions about the world of ethernet.