For large systems, we recommend using Microsoft Windows Server 2008 64-bit. There are three important reasons for this:
• Windows Server 2008 - 64 bit has the ability to utilize server-class hardware, which means being able to run more CPUs and add more RAM as needed. The number of physical processors is limited to two in Windows 7.
• For web hosting, Windows Server offers better performance which plays an important role in StruxureWare Power Monitoring’s web applications such as Reports and Diagrams.
• A 64 bit operating system allows the use of SQL Server 64-bit, which can perform much faster compared to the 32-bit version.
Please note that StruxureWare Power Monitoring is a 32-bit software package. However, 64-bit systems support 32-bit software. The gain in using 64-bit comes from the better performance for what complements StruxureWare Power Monitoring.
Which is more important: CPU or RAM?
They are both important for different reasons. The CPU plays a critical role for executing
StruxureWare Power Monitoring operations. It is especially important when using a large amount of translated devices. On the other hand, RAM is very important for SQL Server. SQL Server is a memory intensive program and will need more RAM for running reports, logging large number of measurements, and other database intensive operations.
How can I improve performance if it is necessary to have more than ten devices on a serial loop?
Due to network architectural limitations, it may not be possible to reduce the number of the devices on a serial loop. In cases like these, there are things that could help improve performance:
• Replace software logging with a data logger (such as an EGX300) to reduce communications traffic on the serial loop.
• If Vista is used to access some of the real time data on this loop, consider using custom diagrams that consolidate the required tags into one diagram instead of using the default diagrams. For example, displaying only Energy and Demand registers from all of the devices on one Vista diagram instead of opening all default diagrams at the same time.
• In Vista, the Update Period (Properties > Updates) can be increased to throttle the
communication. The default Update Period in StruxureWare Power Monitoring is five seconds which can be increased to an amount better suited for the operation.
• The ConnectedThreadPoolSize and LI_PollingPeriod_s registers can be added and set
accordingly to improve the connection performance. See"Advanced configuration parameters" on page 42for additional information.
StruxureWare Power Monitoring as an OPC Server hosting data from translated (non-ION) devices
It is important to keep in mind that there are two cycles of translation when hosting data from translated devices in OPC format. First, StruxureWare Power Monitoring retrieves data from translated devices (see"System components" on page 29for additional information). Then this data gets translated again into OPC format for broadcasting. Therefore, an already heavy
translating process gets used twice to make data available. In a healthy operating network, this is not a concern. However, if there are too many translated devices that are broadcasted in OPC format, it is important to enable only the measurements that are needed. This saves StruxureWare Power Monitoring a considerable amount of system resources and unnecessary network traffic.
How can I measure the bandwidth saturation/utilization of a serial loop?
a. In Management Console, ensure all devices on the loop to be tested are enabled.
b. Apply the desired test load to the devices on the serial loop (for example VIP, Vista, OPC, Diagrams, Tables, or Log Inserter).
c. In the Diagnostics Viewer, drill down into the Communications Diagnostics and select the site of the associated loop.
d. Select the Communication Status tab.
e. Make note of the time, right-click in the Communication Status panel, and select Reset.
f. Let the system gather metrics. For real-time data loads, a few minutes is usually enough. For logging, it is better to leave it for an hour, depending on logging intervals.
g. Make note of the time again, and from the Diagnostics Viewer, obtain the number of Requests, Responses, and Average Response Time.
h. Multiply the Requests by the Average Response Time, and divide that by the difference of the two times noted.
StruxureWare Power Monitoring 7.0 System Design Guide SQL Server clustering
Glossary
A
Aggregation
Combining data from multiple sites to determine total energy usage, demand, and load profiles.
B
Bandwidth
The amount of occupied frequency space, determined by the difference between the high and low frequencies of a transmission band. Bandwidth is used to measure network capacity, and is expressed in Hz.
Bridge
A device that passes data packets between two network segments. Bridges can support a full Ethernet segment port, so each port gets 10 Mbps of bandwidth, allowing a LAN to grow significantly larger. Bridges also filter network traffic to only those packets needed on each segment, increasing data throughput.
D
Dual ring topology
A network topology in which two rings connect each node on a network instead of one network ring that is used in a ring topology. Typically, the secondary ring in a dual-ring topology is used as a backup in case the primary ring fails. In these configurations, data moves in opposite directions around the rings. Each ring is independent of the other until the primary ring fails and the two rings are connected to continue the flow of data traffic.
E EMI
EMI (Electromagnetic Interference) is interference by electromagnetic signals on transmission lines. EMI causes data errors.
Equipotential bonding
Equipotential bonding involves joining together metalwork that is or may be grounded so that it is at the same potential ( voltage) everywhere.
Ethernet
A LAN (Local Area Network) specification. The Ethernet specification describes the implementation of the physical and data link layers of the OSI Reference Model. An extension to Ethernet is Fast Ethernet operating at 100 Mbps. Physical variations of Ethernet include 10BaseF and 10BaseT.
F Filter
An electronic device that attenuates certain frequencies while allowing others to pass through. A high-pass filter lets all signals above a given frequency pass. A low-pass filter lets only frequencies below a given frequency pass. A bandpass filter lets a given band of frequencies pass while attenuating all others.
Full-duplex
Simultaneous data transmission between a sending station and a receiving station. For example, in voice transmissions between two people, they can talk at the same time and still be heard.
H
Half-duplex
Data transmission in only one direction at a time between a sending station and a receiving station. For example, in voice transmissions between two people, only one person can talk at a time and be heard.
Hub
A common connection point for network segments required for star topologies. A hub takes an incoming data packet and copies it to the other ports so that all segments of the LAN can see the packets. Hubs allow LANs to extend beyond normal distance limitations, but all ports have to share a single network bandwidth. A passive hub simply passes data going from one network segment to another. A switching hub reads the destination address of each packet and then forwards the packet to the correct port.
I IED
IED (Intelligent Electronic Device), an instrument that can perform local data processing and storage functions. ION meters are often referred to as IEDs.
IEEE
IEEE (Institute of Electrical and Electronics Engineers), an international organization that produces standards and guidelines covering most aspects of electricity use.
IIS
IIS (Internet Information Services) is a web server application created by Microsoft Corporation and used with Microsoft Windows operating systems.
Impedance
The opposition to the flow of AC current at a given frequency. Impedance consists of resistance, inductive reactance, and capacitive reactance. It is measured in ohms.
StruxureWare Power Monitoring 7.0 System Design Guide SQL Server clustering
IP code
IP (Ingress Protection) Rating used to specify the environment protection of enclosures around electrical equipment.
M
Mesh topology
A network topology in which each component in the network is connected to every other component in the network. This topology has the advantange of continued operation even if a node fails, but can be expensive and difficult to implement.
MTBF
MTBF (Mean Time Between Failure), a statistical estimate of the time a component, subassembly, or operating unit operates before failure occurs.
N Noise
Unwanted electrical signals that distort power signals. Noise consists of high frequency signals (lower than 200 kHz) that are superimposed on voltage or current waveforms and are present on a more or less continuous basis. Noise can be triggered by electronic devices, control circuits, arcing equipment, loads with solid-state rectifiers, and switching power supplies. Noise causes undesirable effects in electronic equipment including PCs and programmable controllers. The problems can be mitigated with filters, improved grounding, isolation transformers, and line conditioners.
P Packet
A unit of information sent over a network. It can contain a header and footer (for synchronization and control) as well as user data.
PLC
PLC (Programmable Logic Controller) is a computerized controller that stores instructions for device operation and sequencing.
R
Rapid spanning tree protocol
A variation of the spanning tree protocol that provides significantly faster response to a topology change. Standard IEEE 8021.D-2004 now incorporates RSTP and obsoletes the original STP standard.
Ring topology
A network topology in which all devices in a network are connected in a loop. Packets travel in a single direction on the ring as they are passed from one device to the next. Each device checks a packet for its destination and passes it on to the next device.
S Sag
A short duration decrease in RMS voltage or current of between 10% and 90% of the nominal. The duration ranges from ½ a cycle to 1 minute. Sags are triggered by fault clearing, startup of heavy loads, or lightning. Sags deprive computers of power, causing unexpected system crashes that lead to lost or corrupted data. Sags can also damage or shut down equipment, particularly motors, and reduce their efficiency or life spans.
SCADA
SCADA (Supervisory Control and Data Aquisition) System, a traditional SCADA system consists of a master station, transducers, and RTUs (Remote Terminal Units). The master station provides the primary operator interface and manages overall system functions, collecting and analyzing data from RTUs as well as initiating control actions. Transducers measure general equipment parameters such as temperatures and pressures. The RTU detects, timestamps and logs setpoint and digital I/O events.
Shielded twisted pair
A two-pair wire medium used in a variety of networks. Shielded twisted pair cabling has a layer of shielded insulation to reduce EMI (electromagnetic interference) causing data errors.
Shielding
A metal barrier, enclosure, or wrapping (around instrumentation and power cables) designed to protect sensitive circuitry and cabling from noise sources (equipment that may generate electrostatic or electromagnetic fields). Shielding reduces coupling between conductors.
Spanning tree protocol
A network protocol that ensures a loop-free topology for any bridged Ethernet local area network. Spanning tree allows a network design to include redundant links to provide backup paths if an active link fails.
Star topology
A network topology in which each device in the network is connected to a central device, such as a switch or hub. All packets sent through the network must pass through the central device to get to its destination. The star topology is one of the most common network topologies
Striping
The technique of dividing logically sequential data into blocks and distributing those blocks to different physical storage devices. Used in RAID configurations.
Swell
A short duration increase in RMS voltage or current of 10% to 80% above the nominal. The duration ranges from ½ a cycle to 1 minute. Swells are not as common as sags. They are usually associated with system faults, but are also caused by switching off large loads and energizing large capacitor banks. One way that a swell can occur is from the temporary voltage rise on the unfaulted phases during a single line-to-ground (SLG) fault.
StruxureWare Power Monitoring 7.0 System Design Guide SQL Server clustering
Switch (in computer networks)
An extension of a bridge, linking four or more full networks. There are two types of switches:
cut-through and store-and-forward. A cut-through switch examines the packet destination address before forwarding it to its destination. A store-and-forward switch examines the entire packet to catch packet errors. Both types of switches separate an Ethernet network into segments, with each segment having 10 Mbps of bandwidth shared by fewer users, resulting in higher performance.
Switch (in electrical circuits)
A device that controls if an electrical circuit is open or closed. A general-use switch, intended for general distribution and branch circuits, is rated in amperes and is capable of interrupting its rated voltage. A transfer switch moves one or more load conductor connections from one power source to another. An isolating switch cuts off an electrical circuit from the source of power. It is intended to operate only after the circuit is opened by some other means.
T
Throttling
A measure employed in communication networks to manage the amount of network traffic.
A typical example of this is by limiting the rate at which a server will accept or transmit data.
By limiting the rate at which a server accepts and transmits data, the risk of network congestion or server crash is reduced.
U
Unshielded Twisted Pair
A four-pair wire medium used in a variety of networks. Unshielded twisted pair does not require the fixed spacing between connections that is necessary with coaxial-type connections.
System Design Guide
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ION, Modbus, PowerLogic, StruxureWare, and Schneider Electric are either trademarks or registered trademarks of Schneider Electric in France, the USA and other countries. Other trademarks used are the property of their respective owners.
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7EN02-0315-00 05/2012