A strength of Cutler-Hammer PowerNet is its ability to use an Ethernet backbone. The Ethernet NetLink and the Ethernet PONI are two products that allow the connection of meters and relays to a standard Ethernet backbone.
A major concern of network administrators when adding computers or metering equipment to a network is the amount of network traffic that will be generated by adding the new components to the network. In a shared network environment all devices or computers must share the available bandwidth on a given Ethernet network. The nature of Ethernet limits the amount of actual traffic on a network to about 30% of its stated bandwidth. Therefore on a 10 megabaud network only about 3 megabaud is available for data movement.
PowerNet devices utilize very little network bandwidth compared to computers with which they often share network space. PowerNet software and hardware products are designed to allow network administrators to manage the amount of traffic new devices create on their Ethernet network. A combination of push technology and controlled polling timing allows network administrators to fine tune the impact of adding new devices onto an Ethernet network already running close to its maximum bandwidth. Administrators may control how often they want updates of parameters by restricting device scan times. Push technology monitors values to see if they have changed before transmitting over the network. Further customization allows administrators to control the push rate, how often parameters are "pushed" to clients requesting new data. If monitored parameters have changed, and a client is looking for new data, then data is updated to the client application at the push rate.
Ethernet NetLink
The Ethernet NetLink is designed to connect a substation or equipment room with several line-ups of power distribution equipment containing up to 200 Cutler-Hammer devices daisy chained together on an industrial twisted shielded pair frequency based network. Ethernet requires point to point wiring, making wiring in this environment costly since an individual wire would be required for each of the 200 devices. Category 5 Ethernet cable is communications cable rated at 300V which can make wire routing a challenge. The NetLink allows a single twisted pair of 600V rated cable be daisy chained between substations connecting all 200 devices through one Ethernet connection.
On board flash memory stores historical trends and event records. This trend data for load profiling and trip event data is captured and stored in nonvolatile ram for later downloading to a personal computer or network server. Up to 6MB of logging space is available, enough to trend energy from 5 devices every 15 minutes for 213 days. The NetLink allows the reliability of your Power Monitoring system to exceed the reliability of your Ethernet system.
Ethernet PONI
The EPONI enables Ethernet communications for a single PowerNet device through a PONI interface. It is designed for applications where a corporate or campus Ethernet backbone is available in close proximity to the metered point and the highest communications speed to a meter is desired.
The EPONIF is designed for electrically noisy environments. It includes a Fiber connection, 10Base-Fl, for complete noise immunity from radiated electrical signals found in power distribution environments. Its 10Base-T connection can be used in parallel with the fiber connection in a redundant wiring architecture in which the EPONI can automatically switch to a good data line in the event of a cable break.
The EPONI supports the IQ Analyzer, The IQ DP-4000, and the IQ Data Plus II. Contact Cutler-Hammer for additional products supported. The EPONI is supported by PowerNet versions 1.10 and later.
Ordering Information
PRODUCT / CATALOG NUMBEREthernet NetLink / NLxyz(see key below)
Ethernet PONI / EPONI
Ethernet PONI – Fiber Version / EPONIF
Key:
x = E for Ethernet Output, M for Modbus Output, D for Dual Output
y = 1 for One Port, 2 for Two Ports
z = T for 10 Base-T Ethernet Port/AUI; Otherwise, Blank