Limited number of ports with the ‘Listen for Incoming Communication’ ioControl command

Applies To:

SNAP-PAC-S1
SNAP-UP1-ADS
SNAP-UP1-M64
SNAP-UP1-D64
SNAP-LCE

Versions Affected:

The limitation exists in all versions.

Symptoms:

If the Listen for Incoming Communication command in ioControl is used repeatedly with a different port number, eventually the command will return an error. The maximum successful calls to the command and error number returned, will vary based on the firmware and user application as far as the number of Ethernet communication handles already in use.

In currently available firmware for SNAP-UP1-ADS, SNAP-UP1-M64, SNAP-UP1-S64, and SNAP-LCE, the maximum is 64 with error -49 No more connections are available. Maximum number of connections already in use.

The SNAP-PAC-S1 can open up to about 100 listening sessions and the SNAP-PAC-R1 can open up to about 75 listening sessions. Both return -438 Could not create socket. The number of sessions is subject to available memory.

Resolution:

The ioControl Command reference for this command will include the above information.

Questions?

Contact: Opto 22 Product Support.
Phone: 800-835-6786 or 951-695-3080
Email: support@opto22.com

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