Saved Settings Startup Action

Modbus RTU Communications provides you with the option to reduce normal and/or recovery start up time by saving device characteristics for subsequent re-use.

Important: Saved Settings Startup Action is intended for devices whose characteristics, such as the memory size, do not change. If the settings change, make sure they are deleted .

Note: Saved settings startup is supported only for devices where the number of coils and inputs are evenly divisible by 8.

Select the Saved Settings Startup Action tab in the Modbus RTU Communications Port Properties dialog box.

Selections can be made for the following.

Normal startup.

On Recovery Startup

Normal Startup

Normal Startup occurs when CIMPLICITY starts.

CIMPLICITY is started either when:

The computer is booted up or

A CIMPLICITY user starts the project.

Options for each of the startups are as follows.

Get settings from device

Defines the actions that the device communication interface takes to determine the supported memory types and ranges for a specific device.

Use saved settings

Checked: The device communication interface will use the stored settings to define the device-specific memory types and ranges.

The device configuration data is recorded and stored for later use.

Options if Use saved settings is checked are:

Option

Description

Validate settings

Checked

The device communication interface will query the high range of each memory range as a quick check to confirm that the memory type and range represented is valid.

 

Clear

The device communication interface will not do a quick check.

On failure, get settings from device

When using saved settings, failures may occur.

Two typical failures are:

An integrity error is detected in the saved information.

There is a  failure to verify a memory range when Validate settings is selected.

 

Checked

When a failure occurs the device communication interface will immediately attempt to determine the valid device information using the standard method for obtaining the information.

 

Clear

When the failure occurs, the:

Device will immediately be marked down.

Valid device information will not be collected during initial startup. It will be determined later during retry processing.

On Recovery Startup

Recovery startup occurs after:

A cluster fails.

Process health kills a project as a result of a process failure.

Options for On Recovery Startup are the same as they are for On Normal Startup.

More information

Modbus RTU port configuration.