- ページ 27

デジタルカメラ Baumer EXGのPDF ユーザーマニュアルをオンラインで閲覧またはダウンロードできます。Baumer EXG 42 ページ。 Gigabit ethernet

5. Interface Functionalities

5.1 Device Information

This Gigabit Ethernet-specific information on the device is part of the Discovery-Acknowl-

edge of the camera.

Included information:

▪ MAC address

▪ Current IP configuration (persistent IP / DHCP / LLA)

▪ Current IP parameters (IP address, subnet mask, gateway)

▪ Manufacturer's name

▪ Manufacturer-specific information

▪ Device version

▪ Serial number

▪ User-defined name (user programmable string)

5.2 Packet Size and Maximum Transmission Unit (MTU)

Network packets can be of different sizes. The size depends on the network components

employed. When using GigE Vision

to use larger packets. On the one hand the overhead per packet is smaller, on the other

hand larger packets cause less CPU load.

The packet size of UDP packets can differ from 576 Bytes up to the MTU.

The MTU describes the maximal packet size which can be handled by all network com-

ponents involved.

In principle modern network hardware supports a packet size of 1500 Byte, which is

specified in the network standard. However, so-called "Jumboframes" are on the advance

as Gigabit Ethernet continues to spread. "Jumboframes" merely characterizes a packet

size exceeding 1500 Bytes.

Baumer EXG cameras can handle a MTU of up to 65535 Bytes.

5.3 Inter Packet Gap

To achieve optimal results in image transfer, several Ethernet-specific factors need to be

considered when using Baumer EXG cameras.

Upon starting the image transfer of a camera, the data packets are transferred at maxi-

mum transfer speed (1 Gbit/sec). In accordance with the network standard, Baumer em-

ploys a minimal separation of 12 Bytes between two packets. This separation is called

"inter packet gap" (IPG). In addition to the minimal IPG, the GigE Vision

lates that the IPG be scalable (user-defined).

- compliant devices, it is generally recommended

IPG:

The IPG is measured in

ticks (described in chapter

5.2).

An easy rule of thumb is:

1 Tick is equivalent to 4

Bytes of data.

standard stipu-

You should also not forget

to add the various ethernet

headers to your calculation.