in reply to: HART command #39 posted by Mike on 23 November 2004 at 10:46:45.
HART command #39 is a relic of the early days of HART (mid-80s) when EEPROMs were not so good at multiple write cycles. At that time it was thought desirable for EEPROM burning to be under user control, perhaps after making or trying several parameter changes. You are right, there is no need for this command any more, and I think it has not been used for new devices for many years now.
The trick is to look at the response to command #0. Byte 8 contains the Device Function Flags, where bit 1 (value 0x02) is 1 if EEPROM control by command #39 is required for this device, or 0 if updating both ways is automatic.