No. The v3.51 firmware was not released for the 140CPU53414x. Firmware version 3.50 will more than likely be the final release for the 534 Unity family of controllers.
Updated July 17th, 2019.
**Attached is each of these two firmware files.
The 140CPU53414B firmware is currently at v3.50. **if using the SFCCNTRL block do not use this version** The 140CPU53414A Less than PV16 firmware is currently at v3.31.
Updated July 17th, 2019.
**Attached is each of these two firmware files.