[time-nuts] Re: GPSDO control programs.

[Bob Camp]

Hi

Unfortunately, the outputs of many GPSDO’s are specific to that design. There is no single 
“standard” way to talk to all of them. That is what drove the development of very unique programs
like Lady Heather and Z38xx. They may or may not put out this or that message by default. This
or that message likely can be turned off with some command(s). 

If it still works with Lady Heather, that suggests it’s not totally broken. It’s likely that some setting is 
now a bit off. The not so simple answer is to grab a terminal program like PUTTY. Get it set up and 
connecting to the device. See what the messages actually are. 

The program is free. You already have the hardware needed. The main fun is working out what 
the baud rate on the device actually is now set to. Often the “simple” approach is to just try the dozen 
or so likely candidates. In a few cases odd settings for data bits and parity might be involved. 

The commands and responses on many (but not all) GPSDO’s are standard serial communication. 
There’s no strange binary stuff involved. You can type it in and read the reply. You can make sense of the 
reply if you have a manual that shows the commands and responses. If *idn? does come back with  E1
as a reply, that should be in the manual. 

Fortunately the HP stuff fits into the “many” category.

These devices are now in the “old enough to vote” category, They are not that common (at low
prices) on eBay. In addition, the GPS modules in them are well into the “roll over problems” range.  
it’s unlikely that anybody will go back and do all of the work to incorporate them in a newer program. 
A *lot* of work went into Z38xx and Lady Heather.

No, that’s not saying one should toss them in the dumpster. Far from it. With some mods (= new
modules) they are very useful items. Even without mods, some of them can be made to show the
correct time and date (at the hardware level).   

Bob

> On Jul 9, 2025, at 11:52 PM, rbenward--- via time-nuts <time-nuts at lists.febo.com> wrote:
> 
> Hi All,
> 
> I've been trying to get my Z3805, Z3801, and my Trimble to work another GPS
> program other than Lady Heather and Z38xx.  On the Jackson Labs GPScon, I
> have the latest version (V2.026 14 Mar 2022).  Back in October when I
> purchased the program, I had it running fine.  Now its not doing anything.
> I can send the *idn? command and the gpsdo  responds, as well as *gps?.  I
> get responses in the command window, but the other windows do not fill up.
> Not the RX status window, not the satellite constellation window, not the
> EFC window, no position..  Nothing.  
> 
> 
> 
> It also does the same thing with VisualGPSView (ver1.1 build 401.  Send an
> *idn? and the response is E1>, which I suspect is not a response at all, but
> just an error.  The Z38xx program works great.
> 
> 
> 
> I am running Windows 11 on a miniPC and using a USB to RS-232 converter. All
> the hardware works with Lady Heather and Z38XX, and this is on two different
> computers, a mini Dell 7020, and an Beelink AMD Ryzen 5(?).  Has anyone run
> into this kind of problem before?  It's frustrating, like the two programs
> can interrogate, display he response, but it can't parse the data into their
> respective destinations.
> 
> 
> 
> 
> 
> Does anyone have any other GPSDO programs they use?
> 
> 
> 
> Regards,
> 
> Bob
> 
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