BusManager用于讀取和檢查實(shí)際的驅(qū)動(dòng)器配置。它

也用于恢復(fù)斷開(kāi)的通信鏈路。正常通信至

斷開(kāi)的鏈路被掛起，直到報(bào)告鏈路被恢復(fù)為止。

如果BusManager功能被禁用，則認(rèn)為通信是循環(huán)的

并且是連續(xù)的。缺少驅(qū)動(dòng)器會(huì)導(dǎo)致額外的通信，因?yàn)橄?/p>

朝向它連續(xù)地重復(fù)。

在可以選擇特殊I/O通道之前，特殊I/O通道硬件

必須將定義文件導(dǎo)入到項(xiàng)目中。

要將特殊I/O單元添加到CI858，請(qǐng)?jiān)陧?xiàng)目資源管理器中執(zhí)行以下操作：

?右鍵單擊CI858單元，然后選擇“新建單元”。

?選擇特殊I/O通道。

?右鍵單擊“特殊I/O”通道，然后選擇“新建單元”。

?選擇適當(dāng)?shù)腎/O單元。

?選擇該單元的位置（I/O單元的地址），然后單擊“確定”。

?雙擊設(shè)備并調(diào)整設(shè)置中的特殊I/O參數(shù)

選項(xiàng)卡，方法是雙擊值字段。請(qǐng)參閱第頁(yè)的特殊I/O參數(shù)

43.

?將變量連接到“連接”選項(xiàng)卡中的通道。請(qǐng)參閱特殊I/O

第46頁(yè)的功能塊和第44頁(yè)的連接。

?應(yīng)用并關(guān)閉編輯器（Ctrl+U）。

本章介紹了CI858支持的特殊I/O單元，并給出

有關(guān)如何配置中I/O單元的輸入和輸出通道的說(shuō)明

應(yīng)用程序。

I/O單元可以通過(guò)功能塊進(jìn)行控制。所有連接的I/O單元都需要

它們自己的功能塊，該功能塊是根據(jù)I/O單元類(lèi)型選擇的。A.

功能塊有一組定義的輸入和輸出變量以及

內(nèi)部存儲(chǔ)器。它還有一個(gè)運(yùn)算這些變量的算法。當(dāng)函數(shù)

塊被執(zhí)行時(shí)，它評(píng)估其所有變量并為

輸出和內(nèi)部變量。

特殊I/O功能塊存儲(chǔ)在隨

產(chǎn)品通過(guò)將庫(kù)連接到控件生成器中的項(xiàng)目

塊變得可用于應(yīng)用程序。

The BusManager is used for reading and checking the actual drive configuration. It

is also used for recovery of broken communication links. Normal communication to

the broken link is suspended until the link is reported to be recovered.

If the BusManager function is disabled, the communication is assumed to be cyclic

and continuous. A missing drive causes extra communication, because the messages

towards it are repeated continuously.

Before Special I/O Channel can be selected, the Special I/O Channel Hardware

definition file has to be imported into the project.

To add a Special I/O unit to the CI858 proceed as follows in the Project Explorer:

? Right-click the CI858 unit and select New Unit.

? Select Special I/O channel.

? Right-click the Special I/O channel and select New Unit.

? Select the appropriate I/O unit.

? Select the position (address of the I/O unit) for the unit and click ok.

? Double-click on the unit and adjust the Special I/O parameters in the Settings

tab by double-clicking in the value fields. See Special I/O Parameters on page

43.

? Connect variables to the channels in the Connections tab. See Special I/O

Function Blocks on page 46 and Connections on page 44.

? Apply and close the editor (Ctrl + U).

This chapter introduces the Special I/O units supported by the CI858 and gives

instructions on how to configure the input and output channels of the I/O units in the

application program.

I/O units can be controlled with function blocks. All connected I/O units require

their own function block, which is selected according to the I/O unit type. A

function block has a defined set of input and output variables and variables for

internal storage. It also has an algorithm to operate these variables. When a function

block is executed, it evaluates all its variables and computes new values for the

output and internal variables.

Special I/O function blocks are stored in the Special I/O library delivered with the

product. By connecting the library to a project in the Control Builder, the function

blocks become available to the application.