TRICONEX FTA-544卡件,FTA-544配置手册
SRTP客户端通道提供了帮助用户保留TCP的功能连接。其中包括可以建立SRTP的一段时间通道，并指定以给定间隔运行的通道，或以最快的速度运行可能的还可以指定迭代次数，或允许通道运行永远此外，SRTP通道允许对活动的到同一远程设备的通道，其中活动通道的参数，例如更改通道命令类型（读/写）、重复次数，时间段、本地内存地址、远程内存地址等可以是改变。SRTP通道还允许将活动通道的任务重新分配给不同的远程设备（更改远程设备的IP地址等）。
TRICONEX FTA-544卡件然而将任务重新分配到不同的远程设备既不会保留TCP连接，也不会节省创建频道所需的时间。客户端通道和冗余IP在冗余系统中，客户端通道COMMREQ只能从拥有冗余IP地址的单元。因此，用户应用程序逻辑应在LAN接口状态位区域中使用位6，“冗余IP活动”作为一部分驱动客户端通道COMMREQ的启用逻辑。空闲Modbus/TCP连接在90系列和PAC系统可能过早结束Series 90和PAC系统之间的空闲Modbus/TCP连接可能是提前终止。TCP“Keep Alive”之间存在不兼容PACSystems以太网接口和Series 90以太网上的计时器值接口。问题是序列的保持活动计时器的默认值90个模块的设置值比PAC系统高得多。保持Series 90 Ethernet接口和PACSystems以太网接口，Series 90接口高级用户参数wkal_时间应设置为750，以与PAC系统的时间相匹配。具有这样一来，TCP连接将无限期地保持打开状态。注意，同样的问题对于流量不频繁且可以解决的SRTP客户端通道发生通过使用相同的技术。试图打开17个或更多Modbus服务器连接可能显示成功如果超过最大支持的16个Modbus服务器连接如果尝试，TCP连接可能会成功，但随后可能没有数据转移。
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.
