TRICONEX FTA-544卡件,FTA-544配置手冊(cè)
SRTP客戶端通道提供了幫助用戶保留TCP的功能連接。其中包括可以建立SRTP的一段時(shí)間通道，并指定以給定間隔運(yùn)行的通道，或以最快的速度運(yùn)行可能的還可以指定迭代次數(shù)，或允許通道運(yùn)行永遠(yuǎn)此外，SRTP通道允許對(duì)活動(dòng)的到同一遠(yuǎn)程設(shè)備的通道，其中活動(dòng)通道的參數(shù)，例如更改通道命令類型（讀/寫）、重復(fù)次數(shù)，時(shí)間段、本地內(nèi)存地址、遠(yuǎn)程內(nèi)存地址等可以是改變。SRTP通道還允許將活動(dòng)通道的任務(wù)重新分配給不同的遠(yuǎn)程設(shè)備（更改遠(yuǎn)程設(shè)備的IP地址等）。
TRICONEX FTA-544卡件然而將任務(wù)重新分配到不同的遠(yuǎn)程設(shè)備既不會(huì)保留TCP連接，也不會(huì)節(jié)省創(chuàng)建頻道所需的時(shí)間。客戶端通道和冗余IP在冗余系統(tǒng)中，客戶端通道COMMREQ只能從擁有冗余IP地址的單元。因此，用戶應(yīng)用程序邏輯應(yīng)在LAN接口狀態(tài)位區(qū)域中使用位6，“冗余IP活動(dòng)”作為一部分驅(qū)動(dòng)客戶端通道COMMREQ的啟用邏輯。空閑Modbus/TCP連接在90系列和PAC系統(tǒng)可能過(guò)早結(jié)束Series 90和PAC系統(tǒng)之間的空閑Modbus/TCP連接可能是提前終止。TCP“Keep Alive”之間存在不兼容PACSystems以太網(wǎng)接口和Series 90以太網(wǎng)上的計(jì)時(shí)器值接口。問(wèn)題是序列的保持活動(dòng)計(jì)時(shí)器的默認(rèn)值90個(gè)模塊的設(shè)置值比PAC系統(tǒng)高得多。保持Series 90 Ethernet接口和PACSystems以太網(wǎng)接口，Series 90接口高級(jí)用戶參數(shù)wkal_時(shí)間應(yīng)設(shè)置為750，以與PAC系統(tǒng)的時(shí)間相匹配。具有這樣一來(lái)，TCP連接將無(wú)限期地保持打開(kāi)狀態(tài)。注意，同樣的問(wèn)題對(duì)于流量不頻繁且可以解決的SRTP客戶端通道發(fā)生通過(guò)使用相同的技術(shù)。試圖打開(kāi)17個(gè)或更多Modbus服務(wù)器連接可能顯示成功如果超過(guò)最大支持的16個(gè)Modbus服務(wù)器連接如果嘗試，TCP連接可能會(huì)成功，但隨后可能沒(méi)有數(shù)據(jù)轉(zhuǎn)移。
SRTP Client Channels provides features that help the user preserve TCP
connections. These include a period time where one can establish an SRTP
Channel and specify the channel to run at a given interval, or run as fast as
possible. One can also specify a number of iterations, or allow the channel to run
forever. Additionally, SRTP Channels allows channel re-tasking of an active
channel to the same remote device, where the parameters of an active channel,
such as changing the channel command type (Read/Write), number of repetitions,
time periods, local memory address, remote memory address, etc. can be
changed. SRTP Channels also allows channel re-tasking of an active channel to a
different remote device (changing the remote device’s IP address, etc.). However,
re-tasking to a different remote device will neither conserve TCP connections, nor
save on the time it takes to create a channel.
Client Channels and Redundant IP In a Redundancy System, Client Channel COMMREQs can only be initiated from
the unit that owns the Redundant IP address. Therefore, the user application logic
should use Bit 6 in the LAN Interface Status bit area, “Redundant IP Active” as part
of their enabling logic that drives a client channel COMMREQ.Idle Modbus/TCP connection
between a Series 90 and a
PACSystems may be prematurely
terminated
An idle Modbus/TCP connection between a Series 90 and a PACSystems may be
prematurely terminated. There is an incompatibility between the TCP "Keep-Alive"
timer values on the PACSystems Ethernet Interfaces and Series 90 Ethernet
Interfaces. The issue is that the default value of the keep-alive timer for the Series
90 modules is set to a much higher value than for the PACSystems.
To keep TCP connections open between a Series 90 Ethernet Interface and a
PACSystems Ethernet Interface, the Series 90 Interface Advanced User Parameter
wkal_time should be set to the value 750 to match that of the PACSystems. With
this change, TCP connections remain open indefinitely. Note that this same issue
occurs for SRTP Client Channels that have infrequent traffic and can be resolved
by using the same technique.
An attempt to open 17 or more
Modbus server connections may
appear successful
If more than the maximum 16 supported Modbus Server Connections are
attempted, the TCP connection may succeed, but no data may be subsequently
transferred.
