3BSE007949R1以太网卡件
默认网络设置
默认情况下，网络访问方法是异步的。在异步模式下，所有I/O数据仍然连接到时隙，但FIP总线控制器未同步到网络上数据的实际生产和消耗。
传输时隙默认值下表列出了传输时隙的默认设置。参见第3章
有关传输时隙的更详细信息。异步输入扫描在异步I/O扫描模式下，FIP总线控制器扫描来自
FIP网络在网络上生成的时间段，但不同步。这意味着FBC消耗来自网络的数据，而不考虑实际数据
数据出现在网络上的时刻。因此，提供给CPU可能在网络上的不同时间产生。如果对所有人都有必要对于要一致的时隙中的数据，应改为设置同步操作。
在异步I/O扫描模式下，FIP总线控制器连续扫描
在指定时间段输入数据，并使数据可供CPU使用。中央处理器根据扫描集的要求扫描来自FBC的输入数据，每5次扫描等。
异步输出扫描
FIP总线控制器仅在CPU执行包含时隙的扫描集的输出扫描。因此，如果CPU延迟第一次输出扫描，FBC的输出数据将具有不显著的地位一旦CPU执行输出扫描，FBC将刷新输出数据该时隙。
如果CPU执行输出扫描一段时间，然后停止，则FBC的输出数据
在刷新期到期后变为未刷新。（见网络配置FBC参数刷新系数和刷新偏移。如果CPU必须
在输出扫描之间有很长时间，可能需要调整刷新参数以避免网络上有未刷新的数据。）
配置异步I/O扫描默认情况下，在PLC CPU中，所有时隙都分配给固定扫描集#1
是一个异步扫描集，其周期等于扫描周期，没有输出延迟作为该扫描集的一部分，在逻辑执行和逻辑执行后立即扫描输出。
可以定义多达32个异步扫描集，每个扫描集具有不同的周期和输出延迟。可以将任意数量的时隙分配给单个扫描集。但是一个给定的时隙可以仅分配给一个扫描集。PLC CPU中的扫描集有多种系列90–70系统手册中定义的可配置参数（GFK–1192）。
Default Network Settings
By default, the Network Access method is Asynchronous. In Asynchronous mode, all
I/O data is still attached to time slots but the FIP Bus Controller is not synchronized to
the actual production and consumption of the data on the network.
Transport Time Slot Defaults
The following table lists the default settings for the Transport time slots. See chapter 3 for
more detailed information about Transport Time Slots.Asynchronous Input Scanning
In Asynchronous I/O Scanning mode, the FIP Bus Controller scans input data from the
FIP network at the period that it is produced on the network, but asynchronously. This
means the FBC consumes the data from the network without regard for the actual
moment when the data appears on the network. Therefore, the data provided to the
CPU may have been produced at different times on the network. If it is necessary for all
of the data in a time slot to be coherent, synchronous operation should be set up instead.
In Asynchronous I/O Scanning mode, the FIP Bus Controller continuously scans the
input data at the specified period and makes the data available to the CPU. The CPU
scans the input data from the FBC per the requirements of the scan set, e.g. every sweep,
every 5 sweeps, etc.
Asynchronous Output Scanning
The FIP Bus Controller refreshes the output data in a time slot only when the CPU
performs the output scan of the scan set which contains the time slot. Therefore, if the
CPU delays the first output scan, the output data of the FBC will have an insignificant
status. Once the CPU performs an output scan, the FBC refreshes the output data for
that time slot(s).
If the CPU performs output scans for a while and then stops, the output data of the FBC
becomes unrefreshed after the Refreshment Period has expired. (See the Network
Configuration FBC parameters Refresh Coefficient and Refresh Offset. If the CPU must
have a very long time between output scans, it may be necessary to adjust the Refresh
parameters to avoid having unrefreshed data on the network.)
Configuring Asynchronous I/O Scanning
By default in the PLC CPU, all time slots are assigned to Fixed Scan Set #1. Scan Set #1
is an asynchronous scan set with its period equal to the sweep period and no output
delay. As part of this scan set the inputs are scanned before the logic execution and the
outputs are scanned immediately after the logic is executed.
It is possible to define up to 32 asynchronous scan sets, each with a different period and
output delay. Any number of time slots may be assigned to a single scan set. But a given
time slot may be assigned to only one scan set. Scan sets in the PLC CPU have a variety
of configurable parameters that are defined in the Series 90–70 System Manual
(GFK–1192).
