MorganS,
The Honeywell PPT I'm using is a unit from 2000. Attached is the user's manual I'm referring to when I try to program the Honeywell. I'm a bit doubtful on the compatibility because the user's manual is from 2016, and the pictures of the sensors on its cover page are from 2012. However, on page 10 (in Adobe Reader), or page 4 in the original booklet, section 2.4, the initial turn-on response is covered. It is stated that the PPT will generate a typical RS232 response like writing "?01PPT____10__psid". In section 5.3, it gives an example of setting the transducer to give continuous pressure readings and a user message at power-up. I haven't tried this yet, so I'm hoping that it could would, because that is what I have programmed the Paro static transducer to do. If not, I should constantly write the command *00P2 (continuously read pressure). But I'm not sure where I should put this in my code.
And from the user's manual, it also seems like the response from the Honeywell when given a read pressure command should always start with '?'.