Configuring Properties

<< Click to Display Table of Contents >>

 

Configuring Properties

The configuration options available on the configuration window are also accessible in Offline mode, at run time, using the Strings described on topic Configuring Properties Offline. The next figure shows specific configurations for this Driver on the Ping tab.

Ping tab

Ping tab

This tab is specific to this Driver and its configuration options are described on this topic. On the Setup tab, users must select the None item in the Physical Layer option and users can also enable log generation. All other options for IOKit library are ignored by this Driver.

The available options on the Ping tab are described on the next table.

Available options on the Ping tab

Option

Description

Ping Scan

Defines an internal scan time for each Tag, in case of asynchronous or multi-threaded ping commands

Max. Number of Threads

Defines the maximum number of threads to create. If this value is greater than the number of Tags in the application, this Driver creates a thread per Tag. Otherwise, the maximum number of threads is given by this value. If this value is configured as 0 (zero), ping commands are executed synchronously, in the same reading thread of each Tag. Please check the next note for more information about this option

Ping Timeout

Time-out of a ping command

Ping Retries

Number of times this Driver resends ping requests at each occurrence of a time-out before returning 0 (zero) in the Value field of Simple Ping Tags

Use Async Name Resolution

This option enables resolving host names asynchronously, which allows configuring a time-out for that operation by loosing some performance. Use this option only in cases where a DNS (Domain Name System) operation may last longer or fail frequently

DNS Timeout

Time-out to resolve host names, used in case the Use Async Name Resolution option is enabled

Wait On First Read

If this option is enabled, this Driver waits to perform the first ping command during the first read of each Tag, so that it returns a value. If it is disabled, the first reading of a Tag only schedules a ping command and the operation returns no value and does not change any Tag property in an application. A Tag only starts returning values when the first ping command is performed by this Driver. Users must leave this option disabled preferably, because it tends to improve performance

Disable Ping for Inactive Tags

This option allows this Driver to set Tags to an inactive status in their internal scans, if an application is not requesting a reading during a configurable scan period. In an inactive status, the IP address or the host name referring to a Tag is no longer used in internal scans of this Driver. A Tag goes to an active status as soon as a new reading request is received from an application

Disable tag IP after n missed ping scans

Informs this Driver how many internal scans unread by an application must occur before a Tag is considered inactive

Use Single Host Name

This option must be used only for Elipse SCADA. Using this option limits an application to use a single Tag. Its text box allows defining a host name used for an application's single Tag, which must be defined with N1, N2, N3, and N4 parameters as 0 (zero). For Elipse E3, Elipse Power, or Elipse Water, leave this option disabled and use the Device property of each Tag to define a host name. Please check the next note for more information about this option

Use Compatibility Mode

This option allows defining a certain number of data bytes to send in a frame of an echo request of ICMP (Internet Control Message Protocol) protocol. The default value of this option is disabled. Please check the next note for more information about this option

Send n ICMP data bytes

This option indicates the number of data bytes to send in a frame of an echo request of ICMP protocol, if the Use Compatibility Mode option is enabled. Please check the next note for more information about this option

 

NOTES

•Starting with version 2.1 of this Driver, the maximum number of threads is limited to 100. If this Driver is loaded in applications that already configured a greater number, the number of threads is limited to that maximum number of 100 and writes that limitation to its log.

•When the Use Single Host Name option is enabled, always use the Max. Number of Threads option equal to 0 (zero), that is, a synchronous reading.

•The Use Compatibility Mode option was implemented in this Driver because it is relatively common to find servers that do not respond correctly to an echo request without data, whether by any security policy or by implementation problems. In these cases, this Driver may not be successful with a ping command to servers that return success when using a Windows Command Prompt. This happens because a Windows ping command, by default, sends 32 data bytes in a frame of an echo request, while this Driver sends an empty ping command, that is, without data bytes. If this condition is detected in the servers in use, users must enable the Use Compatibility Mode option and define a suitable number of data bytes that can be accepted by a server in the Send n ICMP data bytes option. It is recommended to start with 32 bytes, which is the default value for a ping command in Windows Command Prompt and accepted for most servers. Otherwise, it is recommended to leave this option disabled, keeping a more optimized condition, without data bytes.

•To test the need to use the Use Compatibility Mode option, users can customize the number of data bytes sent in echo requests of a ping command in Windows Command Prompt by using the -l option, Send buffer size. For more information, please type ping /? in a Windows Command Prompt.

Was this page useful?