Siemens SIMATIC NET Dokumentacja Pobierz pdf (Strona 65)

Chapter 5. About the SI7 I/O Driver 55

Purpose

Typically, when a message fails because of a timeout, the cause is a communication

problem with the device. QuickFail lets the driver bypass the problem device to

quickly handle other device messages. Because the driver is not spending

unnecessary time on a failed device, it performs more efficiently.

See Also

The SI7 I/O Driver Features | Understanding Device Timing Properties: Reply

Timeout, Retry, and Delay Time

Feature: Using Simulation Mode

Simulation mode lets you simulate the connection of the SI7 server to the process

hardware. This allows you to develop a process database that reads and writes values

to the datablock addresses that you configure in the Power Tool without using actual

process hardware. Later, when you want to switch to real process hardware, you can

do so without changing your datablocks or process database.

Example

Reply Timeout = 15 (15 seconds)

Retries = 5

Delay Time = 5:00(5 minutes)

Backup Device = none

Global timeout = 10 (10 seconds)

The driver attempts to send a message to the process hardware. After 15 seconds, the device

still has not responded so the driver re-sends the message.

SIMATIC NET determines it is able to send another message. The driver tries to send the

message again. Assuming that it is able to send data for all retries, the driver sends the request

6 times (the first time and then the 5 retries) with 15-second intervals between each attempt.

Each attempt fails; consequently, the driver marks the datablock as failed. If the driver has

messages for other datablocks on the same device, it sends them only once without retries.

The driver waits 5 minutes before attempting to re-establish communication with the failed

device.

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Siemens SIMATIC NET Dokumentacja Strona 65