I'm trying to do the same using either syslog or SNMPv3 but failing as well. I can get the switch to generate a syslog message only after the "write mem" command is issued. I've also been unsuccessful generating SNMP messages when the config changes.
I opened a ticket with support, response below
We do not have a work around for you on the HP devices. If the only message sent via syslog is for a wr mem, that is really the only option.
I tried to search if there were any other syslog messages that the device could be sent. but did not find a reliable source where any conclusion could be drawn.
We do not have a documented process for HP.
I also contacted HP support but since we only have warranty service and not a higher tier the basically told me they can't help much.
Sorry I don't have an answer. If there is anyone out there who does please respond - we would really like to get RTCD working on our HP equipment.