We posted a new technical note on www.mynah.com. Click here to view "Virtual IO Module Network Cable Shielding & Grounding".
Tech Note Summary: The purpose of this technical note is to specify the network cabling and grounding standards for the M-Series and S-Series Virtual IO Modules (VIMs). As always, any questions or comments, please post a reply!
Hi Noelle.
I believe the post is inaccurate.
The faraday cage needs a connection to ground. You would want both ends of the RJ45 shielded. The article says:
" To make sure that only one ground is used, the cable will only have one shielded connection, and the other end will be unshielded. The unshielded end will connect to the VIM and the shielded end will connect to the network switch. This standard holds for the VIMs as well as all network devices within the DeltaV system to avoid multiple grounds."
If you did that, it would leave the VIM floating.
my 2 cents,
-Travis
In reply to Travis Neale:
Hi Travis,
You are absolutely correct. We have updated the article to reflect the change. Thank you bringing that to our attention!
Noelle
Travis is absolutely right. With most network devices, the Ethernet cable would only be shielded at one end to avoid creating multiple grounds. Since we know that VIMs and Controllers use Faraday Shields, which need to be grounded, we will want to use shielded connectors on both ends. In this case, the purpose of the shielded connector is not to connect the RJ45 to earth ground from the VIM/controller side; the purpose of the shield is to connect the Faraday Shield to earth ground at the network switch.