[time-nuts] Re: HP Z3801A project update

[Lux, Jim]

On 2/24/22 11:31 PM, Larry McDavid wrote:
> I give up! Where is this $5 USB-to-RS422 Adapter to be found?
>
> Amazon has such a DTECH adapter for $22.

Indeed the price has gone up substantially - $15

https://www.amazon.com/DSD-TECH-SH-U10-Converter-Compatible/dp/B078X5H8H7


>
> I am using a RS422-to-RS232 adapter and it has been totally reliable 
> for many years. I am not trying to use the pps output via the serial 
> link so any delay in the USB adapter would be irrelevant.
>
> Is anyone successfully using a USB-to-RS422 adapter to communicate 
> with a HP Z3801A? How does the Z3801A software need to be configured 
> for USB or does the USB adapter simulate a RS232 port?

The one I have looks just like a serial port (i.e. it shows up as 
/dev/cu.SLAB_USBtoUART on my mac and is usable with pyserial ) . I 
changed the jumpers on my Z3801 to RS232 a long time ago, so I don't 
know if it would work, but I suspect it would - they're not doing any 
exotic protocols - it's just serial data.

And I've never depended on the timing of the messages - so the USB 
timing isn't important.


>
> A lot was left unsaid in that simple statement below...
>
> Larry
>
> On 2/24/2022 8:53 PM, Lux, Jim wrote:
>> On 2/24/22 7:25 PM, ed breya wrote:
>>> Paul and Hal, I think there may be some confusion here. I modified 
>>> the Z3801A to RS-232 way back when I first got it. My recent post 
>>> was just discussing some of what's in this demo/testing unit thing. 
>>> It's just a translator for TTL/RS-232 for when the GPS RX board (TTL 
>>> serial) is used by itself, hooked to a PC (RS-232), so the WinOncore 
>>> SW can talk to it. When the RX board is inside the Z3801A, it's 
>>> controlled in that environment.
>>
>> These days, since PCs don't have serial ports, you can buy a RS422 
>> USB adapter for $5.  If I were doing it now, I wouldn't bother 
>> reconfiguring.
>