Chinese brand PSU_monitoring rs485 and Mango

[hengst]

almost a whole day , still no clue what is should put in for VER ADR LENGHT COMMAND_INFO CHKSUM

I look for a reference for learn how to read it.....

[phildunlap]

There is an example data frame provided in the document, item 3.5. It's not the most impressive or elucidating explanation, though.

Looks to me like the version is 02 but transmitted as 3032 (so in setting the hex COMMAND point you'd use 3032, I am guessing, as well as the whole upper row. ADR appears to be the address of the device-1 (they say they're using address 3, but encode 30303032 (0002)!) LENGTH will depend on your command, as will the value for COMMAND_INFO. CHKSUM will require adding up the bytes of the message and doing a remainder operation, it's stated what it is in 3.3, but it's a one byte checksum, and perhaps the internet will describe that to you better than this document, if required.

While implementing this will teach you a lot about Mango and this device, I can't help but wonder if it'll save you time and money to use a device that has a standard protocol?

[phildunlap]

Also something is clearly wrong about my understanding of that, since the data length of sending a 3032 is two bytes (0b00110000 0b00110010) but it's clearly stated to be one byte for the version number. Then, why is 02 on the lower row? This is why i don't get over involved in every protocol that comes by... they aren't always easy to make sense of. So is it sending the 7F [LOWER ROW] 0D? Then what is the point of the top row?

[hengst]

I tracked down the software engineer of the device ( how about that , gehehe ) he is writing a excel sheet for frame calculation Monday.

[hengst]

playing and gambling, ( couldn't wait till Monday ) i found the command :

7e 30 32 30 30 30 31 34 32 30 30 30 30 30 32 30
30 30 31 36 43 0d

( request node ID command )

will result in :

~02000142040000AD or

7e 30 32 30 30 30 31 34 32 30 34 30 30 30 30 41 44

I found this with the tool : https://sourceforge.net/projects/scriptcommunicator/
as i almost work all the time with Linux, this was a golden tool to play around with the commands.

i used these settings for the usb-rs485 communication :

[hengst]

"
While implementing this will teach you a lot about Mango and this device, I can't help but wonder if it'll save you time and money to use a device that has a standard protocol? "

I know,
i ordered it with the idea to use it as with a build in SNMP agent ( as most network devices have these days ) but i didn't look good at the specs, as a result i cant add it to my ( LibreNMS ) monitoring, because its a "dumb" device.

The device is sold as width TCP/IP connection option and default rs485. ( i bought width both )
as i also added a Kwh meter to the setup, ( see topic SDM120-ModBus ) which is also rs485(ModBus) i needed another monitoring tool. and it looks like Mango is filling the gap here, as it does SNMP and rs485(modbus) etc..

As its a VERY cool thing to build and learn, and by posting the results ( in the end as a HOW TO summary ) i am contributing my part to the community's , i am convinced it will help others.

When i got it running it also benefits "Mango" , as then we are going to use it at customers for monitoring anything the want.
Anyway i love it already very much.

so, back to lab.

[hengst]

alright. i got everything complete.

at the point i had figured out how the frame structure functioned, i got some explanation from the other side of the world.

it was in Chinese language, but i have translated it with big brother google.

0_1477746072797_io-codes-recti_translated.pdf

So i think its time to get something done in Mango,

[phildunlap]

Nice! You should be able to test the examples in that document by simply setting 'COMMAND' to the hex (without the spaces, I would think) and checking the RESPONSE point. Then you can experiment with either parsing the values out through regex serial points or implementing the extractMessageInformation function in the point link. You can still use regex in the script, doing the regular JavaScript syntax:

var messageData = /7E(.*)0D/.exec(RESPONSE.value); //source.value in the actual point link script
var messageBody = messageData[1];

[hengst]

Jup, that works :

"
implementing the extractMessageInformation function in the point link. You can still use regex in the script, doing the regular JavaScript syntax:

that is new for me.. but banging my head on the desk and grabbing a cold beer and we are good to go another few hours gehehe.

Thanks for the pointers Phil.

[phildunlap]

Nice! That looks like the ASCII (since it doesn't begin with HEX) payload perhaps? Maybe it would be better to just do the regex parsing on the Serial Data source points, then, if you don't have to do any of the conversion to or from hex.

[hengst]

I had a little throwback....

after i did get this response i was lost in how everything worked in Mango,
so i thought it would be good to start over from scratch.

also i changed the source from "serial data source" to " tcp/ip" data source ( as that is what i need to use in the end )
( the PSU happens to have both options to get the information )

that shouldn't make a big difference in the working flow of mango i think.

i tested the commands over tcp/ip with SerialComm program to confirm and it works just like Serial.

[phildunlap]

"Shouldn't make a big difference..."

I wouldn't think so either. Do you still have the same setting for sending hex? You can always test the TCP/IP data source against netcat, to see what's coming out of it. Simply nc -l 9876 and point the TCP/IP data source at that machine's 9876 port.

[hengst]

9876 would than be the port i use i guess ? ( which is 9999 in my case )

[hengst]

This post is deleted!

[hengst]

I used tcpdump , and looks like there is interaction,

[hengst]

Yes , data is incoming.

now whats next ?

[hengst]

i know i have to get the values out of the returned Hex, with some ( java? ) code
( in the script like in the second post probably ).

how does such code typical looks like.

get states of modules :

returned code :
7e30323030303134323030303032373432353641334437424543434343434430303030303030303345393939393941303030303030303034314338303030303431433830303030303134314338303030303030303030303031 3030303145350d

following manuals :

7e3032303030313432303030303237 ( length of data )
3432353641334437 Bus voltage-float: D7A35642=53.66
4245434343434344 Battery 1 voltage
3030303030303030 Battery 2 voltage
3345393939393941 Load current
3030303030303030 Total module current
3431433830303030 Battery temperature-float: 0000c841=25
3431 Number of modules:
4338303030303031 Environment humidity
3431 System alarms
4338303030303030 Batteries and environmental alarms
3030 Reservation
3031 State of charge: 1 float charging
30 30 Relay alarm high byte
30 31 Relay alarm low byte
45 35 0D

[phildunlap]

You could get the hex for any of these by doing something like...

var busVoltage = /[0-9A-Fa-f]{46}([0-9A-Fa-f]{8}).*/.exec(messsage);
var extractedValue = busVoltage[1];

Using the position in the message to know where to extract them (so, after 46 characters, capture the next 8 is what that regular expression suggests). I'm not sure what the float encoding is (how does D7A35642=53.66?), so I can't really offer too much help there. Some people are talking about a hex to float function here: http://stackoverflow.com/questions/5055723/converting-hexadecimal-to-float-in-javascript

It looks like you're working with the ASCII encoded values again, so while you're playing with the script check out the output of

function toASCII(message) {
  var result = "";
  while(message.length > 1) { //parse two characters at a time
     var charCode = message.substr(0, 2);
     result += String.fromCharCode( "0x" + charCode );
     message = message.substr(2); 
  }
  return result;
}
print( toASCII(message) );

In case that's useful.

[hengst]

yes, that float things is special, i figured out is has something do do with "reversed"

http://www.scadacore.com/field-applications/programming-calculators/online-hex-converter/

[hengst]

pffff, drives me crazy. putting pieces of code in the script only complains about no variable set and stuff and i don t know in what order and place to put the code.
so,
now i started again from scratch. but same settings do not get any data anymore.
( i see it coming in tcpdump )

only in terminal i see :

removing everything. start from beginning. same result. this happened me twice now.

rebooting..