poking rs232 port BMS

On Wed, 6 Nov 2019 05:51:45 -0000 (UTC), Jasen Betts
<jasen@xnet.co.nz> wrote:

>On 2019-11-05, legg <legg@nospam.magma.ca> wrote:
>> I've got a battery management unit that is reluctant to 
>> demonstrate functionality. The vendor's terminal com 
>> software seems non-functional (will not install).
>>
>> So far the only evidence of life is a control line (one 
>> of three) hard on, and rare /XFFE /FFF signalled outputs 
>> on the rs232 port. Internal DC-DC fails to power LEM 
>> sensor. Balancing terminals seem inactive.
>
>
>FF is a single narrow pulse on the data line FE is a slightly wider
>pulse, are you sure you have the baud rate set correctly?
>uising a too low rate can cause this.
>
>> Can anyone recommend a tutorial on poking a serial port 
>> for status / data register contents ?
>
>poke at it with leds and resistors, or theres software that can do
>that too. I use statserial.

Maybe it's modbus where you have to hit it with an address, a command,
data and a CRC to get it to respond correctly ?  

OR some other proprietory system but still may need prodding to
respond ?

Modbus and CANbus is common for BMS's as far as I know but other
systems exist too of course

On Tuesday, November 5, 2019 at 8:32:39 AM UTC-5, legg wrote:

One option:
Get a RIGOL oscilliscope with the free "advanced trigger" options installed.
There's one on sale right now for around $300.  (at TEquipment.net)

You can decode the bus, (inverting if need be).

We do a lot of RS-232, 485 and Modbus stuff here, and lately my Rigol DS2072A has been a life-safer for weird comm problems.

Good luck.
BTW:  I just posted a similar Chinese problem regarding a new laser etcher we got, so I feel your pain.  You would think for all the tariff dollars flowing out of bank account we would at least get a User Manual in English!?

As for Chinese software, I've always wondered which works best:  The actual software, or all the spam-hack virus bloatware it loads.

On Tue, 05 Nov 2019 08:36:39 -0500, legg <legg@nospam.magma.ca> wrote:

>I've got a battery management unit that is reluctant to 
>demonstrate functionality. The vendor's terminal com 
>software seems non-functional (will not install).
>
>So far the only evidence of life is a control line (one 
>of three) hard on, and rare /XFFE /FFF signalled outputs 
>on the rs232 port. Internal DC-DC fails to power LEM 
>sensor. Balancing terminals seem inactive.
>
>Can anyone recommend a tutorial on poking a serial port 
>for status / data register contents ?
>
<snip>

Just had J1939 dumped in my lap. I'm afraid that without 
mfr's com SW, it is beyond a bit of poking.

RL