KB84288
Published: November 25, 2015
Revision: 1.1

Incorrect free space shown for microSDHC cards on SNAP PAC controllers


Applies To:

SNAP-PAC-S1
SNAP-PAC-S1-FM
SNAP-PAC-S1-W
SNAP-PAC-S2
SNAP-PAC-S2-W
SNAP-PAC-R1
SNAP-PAC-R1-B
SNAP-PAC-R1-FM
SNAP-PAC-R1-W
SNAP-PAC-R2
SNAP-PAC-R2-FM
SNAP-PAC-R2-W

Versions Affected:

Firmware R9.2a - R9.5f

Resolved In Version:

9.5g


Symptoms:

If you are using a microSDHC card that is 4–32 GB in size in a PAC controller and there is more than 2 GB of free space on the card, then if you read the available space of the card using one of the following methods, the result may not be correct:

  • Use the "Get Available File Space" command in a PAC Control strategy
  • Use PAC Manager, PAC Control strategy logic, or any other method to read OptoMMP address 0xF7002204

This occurs because the OptoMMP address only supports a 32-bit value and PAC Control only supports signed 32-bit values.

Workaround:

  • For firmware versions below R9.5g, there is no workaround.
  • Starting in firmware version R9.5g:
    • If you are using the PAC Control "Get Available File Space" command or you read OptoMMP address 0xF7002204, then the free space returned will be clamped to 2 GB. For example, if the actual free space is greater than 2 GB, it will return a value corresponding to 2 GB; if the actual free space is less than 2 GB, it will return the correct value.
    • If you read a new OptoMMP address of 0xF7002208, it will return a 64-bit value that is correct.

Resolution:

Opto 22 has resolved this issue.

Questions?

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


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