Will the ADAM-6000 take advantage of shielded network cable?

Yes. The ADAM-6000 Series I/O modules, as well as the ADAM switches, hubs, and Ethernet gateways, have shielded RJ-45 sockets that accept standard RJ-45 plugs, shielded or unshielded.

Ethernet communication tends to be very reliable. The physical characteristics of Ethernet cable are very similar to serial RS-422 cable. Like RS-422, Ethernet uses twisted pair that gives it excellent immunity to ambient electromagnetic interference, EMI. However, significant EMI, such as that created by motor starters, may still disrupt twisted pair communication. Proper shielding of the communication cable will contribute significant protection against such spikes. The concept is that the EMI will induce a current in the shield, but not penetrate it significantly. The induced current will be drained to ground harmlessly through the shield.

However, higher sustained current flow in the shield will create a secondary field that can be significant, especially in ground loops. That is why proper connection of the shield is important. Normally, shield wires, sometimes called drain wires, should be connected only on one end. The most solid and stable ground should be the end that is connected, the other end should be left floating. The reason is that earth grounds are rarely at or even near identical potential. As a result, if both ends are connected and the potential is different, current will flow. Because the resistance of shielding is very low, even very small potential difference between earth grounds can result in very high current flow. Earth potential is persistent and typically will not equalize through a cable shield. So, the current will remain relatively continuous.

Ground loops can produce very mysterious behavior in electronic equipment which often frustrates and impedes troubleshooting efforts. Although shielding may be perceived as an optional protection against electromagnetic noise, it can be the source if not properly connected. The shielded RJ-45 plug has a conductive metal wrapper around the plug that makes contact with the metal sheath on the inside of the RJ-45 socket. To insure that only one end of an Ethernet cable is connected to earth ground, make sure the end floating open does not have the cable shield or drain wire connected to the metal wrapper on the plug or touches the RJ-45 receptacle metal sheath in any way. Make sure that the grounded end has a reliable very low resistance path to ground. If an ADAM-6000 module is being used as the grounded end, make sure the ground screw on the case is connected to a good earth ground.

Offer Code: N031204W3