PW_BLOCK_SIZE

For

Project Wizard

Project

Purpose

To specify how many IP addresses the Project Wizard will scan in a single block.

Comment

PW_BLOCK_SIZE defines the IP address block size that the Project Wizard uses to determine how many IP address requests to make at one time. This is particularly useful in Windows XP SP2 and Windows 2003 Server SP1, whose security enhancements limit the number of outgoing unanswered TCP/IP requests. The security limitation can prevent the Project Wizard from finding existing PLC's in a network.

If the Project Wizard does not find any PLC's that you know are on your network do the following.

  1. Open the Windows Administrative Tools>Event Viewer

  2. Review the Event Viewer to see if there is a TCP/IP error.

If there is a TCP/IP error the Windows security enhancements are interfering with the Project Wizard's functionality.

  1. Add PW_BLOCK_SIZE to the project.

  2. Assign a value from 1 through 64.

Recommended: Assign a value that is less than 5. The slower the network, the lower the number must be.

Value

An unsigned integer within the valid range of 1-64.

Note: 64 will be used for any value entered that is higher than 64.

Default Value

5

Example

The Project Wizard defaults to a block size of 5 when PW_BLOCK_SIZE is not present.

An example network has 100 IP addresses to scan.

The PW_BLOCK_SIZE = 5.

The Project Wizard makes 5 requests at one time (1 request/1 IP address).

The Project Wizard will make 5 requests x 20 times, to include the 100 IP addresses.

 

More information

Global parameters.