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L4400A Firmware Revision History

Changes from 2.41 to 2.43

  • L4450A: Fixed reset routines (*rst, syst:cpon) to allow handshaking to be reset correctly
  • WebUI: Increased size of the buffer for HTTP headers (occasionally refusing connections from certain hosts)

Unit firmware changes:

  • L4421A (1.20 to 1.21)
    - Critical defect fix: modified temperature sensor read routines to eliminate the 'internal error 10' race condition that was introduced during the upgrade to mainframe rev 2.41.
  • L4433A (1.14)
  • L4437A (2.10)
  • L4445A and 34945EXT (1.40)
  • L4450A (2.30)
  • L4451A (2.16 to 2.17)
    - Trigger out output signal was not being disabled correctly and was always driving the output.
  • L4452A (2.10)

Changes from 2.33 to 2.41

  • Fixed internal state machine timer to account for worst case interrupt jitter when scheduling events
    - In rare cases an interval scan could get delayed in time by ~3 minutes because reloading the hardware timer was interrupted just as the scan interval expired.

Unit firmware changes:

  • L4421A (1.18 to 1.20): Fixed temperature reference measurements:
    - Repaired defect related to a loss of resolution on the temperature reference junction (LSBs no longer set to 0).
    - Increased number of samples over which reference temperature is averaged.
    - Fixed defect where a negative reference value failed to invert the fractional part of the reading, causing it to be off by as much as 1 deg C for temperatures < 0.
  • L4433A (1.13 to 1.14)
  • L4437A (2.09 to 2.10)
  • L4445A and 34945EXT (1.39 to 1.40): Fixed defect on the 34945EXT that could cause unrecoverable firmware if power is lost during a firmware update.
  • L4450A (2.30)
  • L4451A (2.16)
  • L4452A (2.10)

Changes from 2.25 to 2.33

  • Added support for new generation of microprocessor on units shipped after June 1, 2008

Unit firmware changes:

  • L4421A (1.17 to 1.18): added support for new generation of microprocessor
  • L4433A (1.12 to 1.13): added support for new generation of microprocessor
  • L4437A (2.08 to 2.09): added support for new generation of microprocessor
  • L4445A (1.28 to 1.39): added support for new generation of microprocessor
    improved power supply overvoltage detection
  • 34945EXT (1.28 to 1.39): added support for new generation of microprocessor
    improved power supply overvoltage detection
  • L4450A (2.29 to 2.30): added support for new generation of microprocessor
  • L4451A (2.15 to 2.16): added support for new generation of microprocessor
  • L4452A (2.09 to 2.10): added support for new generation of microprocessor

Changes from Revision 1.00 to 2.25:

  • L4445A: Corrected race condition that could cause an unintentional flash memory erase at boot
    - 34945EXT has its own firmware. It's recommended that 34945EXT be updated with the L4445A as well to not experience conflicting firmware issues.
  • L4400A: Fixed *RCL of analog bus states in 4-wire RTD mode
  • L4400A: The sequence form of SOURCE:DIG:DATA no longer defaults to BYTE width. It is now using the currently selected channel width
  • L4400A: Removed vulnerability that made it possible to short modules together by updating the monitor channel while waiting for a scan trigger

Revision 1.00 – Initial release

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