HP50g serial communication with 3rd party device

[Marakasmalan]

Apologies, this thread was by mistake first posted in the Articles Forum - I reported to mods to have it moved. Sorry!

Hello Folks,

Firstly, thanks for maintaining this site and the forum.

Secondly, I tried to research as much as possible within my comprehension prior to posting this question.

Some of the advice on similar threads seems to be above my uneducated mind, but I am on the right track I believe. Some clarification would however be appreciated.

I am trying to communicate via RS-232 port with a 3rd party device. Though the end goal is somewhat more complicated, the first step is to send an instruction or a command, to which the device will send a reply.

Now, the instructions from the 3rd party device is as follows:

"All communication should be done at a rate of 115200 bps with 8 data bits, 1 stop bit and no parity bits.
No flow control should be performed.

All commands sent to the device and responses sent back have the following basic format:
<Prefix > . <Variable> <Operator> <Value> <CR> (and/or) <LF>"

This means some obvious settings for the IOPAR list which makes sense, except the protocol. And the hpcalc.org cable, which I have.

First question:
What protocol is used here, as Xmodem or Kermit is not specified?

Should I instead make use of a program such as dterm or terminaltor 0.45 (which I am slightly carefull because of the ML programming being more unintelligable to me than the dterm source code, the latter of which I can make some sense)

Or can I simply program instructions such as:

<< "<Prefix > . <Variable> <Operator> <Value>" 13 CHR + XSEND >>

How will the calculator know it is suppose to receive after sending the command?

Before I start programming a list off different commands, I first want to establish the frimware version of the device, the command should be as follows:

Description: Query Firmware Version
Example: <CR>Main.Version?<CR>

Any advice in this regard would be greatly appreciated.

Thanks a lot

Marakasmalan