Network Considerations

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Network Primer

The IP address provides two pieces of information: the network ID and the host ID. The network ID must be unique among all network subnets within a connected Internet. It identifies the network subnet to which a host is connected. The host ID must be unique among hosts within a network subnet and identifies the host within the subnet.

Network subnets connected to the public Internet must obtain an official network ID from the Network Information Center (800-444-4345 or nic@nic.ddn.mil) to preserve the unique network ID’s within the Internet. However, if you never intend to connect to the Internet, you’re free to select your own network IDs.

The IP address consists of four numbers. Each of these four numbers can have a value in the range 1 to 254. An IP address is written in the form w.x.y.z. For example, "198.178.246.10" (or "C6.B2.F6.0A" in hexadecimal) is a valid IP address.

There are three commonly used classes of IP address assignment as follows:

Class

A

B

C

w Value

1 to 126

128 to 191

192 to 223

Net ID

w

w, x

w, x, y

Host ID

x, y, z

y, z

z

Available

Subnets

126

16384

2097151

Available

Hosts

16777214

65534

254

The following are reserved addresses and may not be assigned to hosts:

127.0.0.0

128.0.0.0

191.255.0.0

192.0.0.0

223.255.255.0

w = 224 through 255 with x, y, and z equal to any value

Most IP subnets have Class B or C Net IDs because there are quite a few of these available. You may be able to get a Class A Net ID, but there are so few of these available (only 126 world-wide) that they are rarely issued and most are already assigned.

Most companies get one or more Class C assignments, which means that there is a limit of 254 hosts per network subnet.

The TCP/IP software separates the Net ID portion of the IP address from the Host ID portion using the user-assigned Subnet Mask. This mask looks like an IP address, but has a bit set in each bit position of the portion of the IP address that is in the Net ID portion. For example, the Subnet Mask 255.255.255.0 sets the Net

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Fluke 2640A, 2645A user manual Class Value, Net ID Host ID Available Subnets, Available Hosts

2645A, 2640A specifications

The Fluke 2640A and 2645A are advanced bench multimeters that represent a significant leap in measurement technology, designed primarily for electrical engineers and technicians who require precision and reliability in their readings. These multimeters are built to cater to complex applications in manufacturing, research, and development.

One of the standout features of the Fluke 2640A and 2645A is their high accuracy. With specifications that can reach up to 0.0035% DC Voltage accuracy, users can trust that their measurements will be consistent and precise. This is especially critical in fields like automated test equipment (ATE) where exact measurements can be crucial for product quality and safety.

Both models incorporate a large, easy-to-read display, making it convenient for users to view measurement results clearly from a distance. They also feature a wide measurement range, capable of handling a variety of tasks, from basic voltage and current measurements to more complex tasks such as resistance and temperature measurements with appropriate sensors.

The multimeters also stand out with their advanced data logging capabilities. The Fluke 2645A, for instance, can store up to 10,000 readings, allowing for extensive data collection and analysis without the need for constant monitoring. This is beneficial for long-term studies or processes that require continual oversight.

Connectivity is another key characteristic. Both the 2640A and 2645A support USB and RS-232 interfaces, which enable easy integration with computers and other devices for seamless data transfer. This feature is important for engineers who rely on software for data analysis and visualization.

Another notable technology included in these models is the Fluke Connect app compatibility, which allows users to remotely monitor measurements from their smartphones or tablets. This capability provides added flexibility, enabling technicians to work hands-free while still keeping an eye on process measurements.

Additionally, the Fluke 2645A comes with a graphical display option, allowing users to visualize measurement trends over time. This graphical representation can be invaluable for diagnosing issues or observing patterns in data.

In conclusion, the Fluke 2640A and 2645A multimeters offer exceptional performance with their high accuracy, extensive data logging, connectivity options, and advanced visualization capabilities. These features make them indispensable tools for professionals in a variety of fields, ensuring that they can achieve reliable results in their measurement endeavors.