The most accurate method to determine the software version of an RFC-1/B is to go online with it and enter the command '78'. The RFC-1/B will respond with the software version.

• In version 2.x, the response will be 2.00 through 2.03
• In version 3.x, the response will be 3.00 through 3.08
• In version 4.x, the response will be "software version" 4.00 through 4.24
• In version 5.x, the response will be "software version" 5.00 through 5.10

This method will always read the correct software version even if the RFC-1/B has been updated.

If you have the serial number from your RFC-1/B, we can determine the major software version that originally shipped in the unit when it left the factory. This may not be the version that is in the unit now if it has been updated. If you need the exact firmware revision, the best way is to read it as described above.