<![CDATA[A Bit Stuck on Writing Multiple MODBUS Registers]]>Hey Guys, long time no post haha. I've got a tricky one here...

I have a MODBUS device I need to write two things simultaneously to to get the required function to work.
I have to write a function code of 2 to register 4104 and key of 35702 to 4105 simultaneously.

0_1595277160168_9bbef587-98b6-4caa-bfa7-2f0ba991255c-image.png

I've tried putting the data in as hex or just decimal versions, on a 4 byte / 2 byte. Hair is being pulled out now and I don't have much left :P

I've tried the fixed length option also as it allows you to select number of registers, but I can't work out how to separate the two values.

This has to be something simple but I'm a bit lost with the syntax. Any help would be most appreciated. I'm a bit confused on this one.

Cheers
Dan

]]>https://forum.mango-os.com/topic/4880/a-bit-stuck-on-writing-multiple-modbus-registersRSS for NodeWed, 10 Jun 2026 09:11:29 GMTMon, 20 Jul 2020 20:13:04 GMT60<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 13:13:49 GMT]]>exactly

]]>https://forum.mango-os.com/post/25546https://forum.mango-os.com/post/25546Wed, 22 Jul 2020 13:13:49 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 11:29:54 GMT]]>I tried a little bit of script magic to see if it would do it at the same time, but I think still not quick enough..
0_1595418651817_c2b6021c-e189-4a1e-8117-28a42226f4b1-image.png

0_1595418680470_2482c105-ebe7-4717-bdf9-643997d448b8-image.png

I guess I need to combine the two 16 bit values into one 32 bit value, then write that to the single register, which should extend to the second yeh?

]]>https://forum.mango-os.com/post/25545https://forum.mango-os.com/post/25545Wed, 22 Jul 2020 11:29:54 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 10:54:31 GMT]]>You should capture the command with Wireshark and see if it matches what you are expecting.

]]>https://forum.mango-os.com/post/25544https://forum.mango-os.com/post/25544Wed, 22 Jul 2020 10:54:31 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 10:53:26 GMT]]>ok sweet as, thanks for that I'll give it a go

]]>https://forum.mango-os.com/post/25543https://forum.mango-os.com/post/25543Wed, 22 Jul 2020 10:53:26 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 10:52:40 GMT]]>I may be wrong here but I am pretty sure that the only way that mango will write them in the same command is if you use 1 x 4-byte data point.

]]>https://forum.mango-os.com/post/25542https://forum.mango-os.com/post/25542Wed, 22 Jul 2020 10:52:40 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 10:47:08 GMT]]>So I emailed DSE from their website contact form for shits and giggles, not really expecting to hear back... A nice fella from the UK emailed back almost immediately with all the official docs on the thing. I thought that was awesome.. Anyway, here's a more explanatory version of what I had found originally...

0_1595416069873_69719d29-dae3-4c8b-adb2-d135b9f6d889-image.png
0_1595416123361_de62073f-3f72-412c-a056-53c21c664afa-image.png

So looking at that, I should be sending 35702 to 4104 and 29833 to 4105
:)
I'll give that a go..

]]>https://forum.mango-os.com/post/25541https://forum.mango-os.com/post/25541Wed, 22 Jul 2020 10:47:08 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:21:53 GMT]]>OK, thanks Craig. I have a data point I made earlier which I will go back to and see what it does.
Thanks

]]>https://forum.mango-os.com/post/25540https://forum.mango-os.com/post/25540Wed, 22 Jul 2020 07:21:53 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:19:36 GMT]]>If I was troubleshooting I would create data points instead of using the modbus tool. It looks like you are using quite an old version of mango and I have had issues with the modbus tool in older versions. I think it would be worth cancelling that out of the troubleshooting.

]]>https://forum.mango-os.com/post/25539https://forum.mango-os.com/post/25539Wed, 22 Jul 2020 07:19:36 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:16:18 GMT]]>Yeh the Mango instance is a few hundred ms away. It seems to work fine reading in voltages and RPM's and the like. Just been playing up a little today probably due to the weather.
Even when it was working fine the write function still didn't seem to be the correct syntax.

]]>https://forum.mango-os.com/post/25538https://forum.mango-os.com/post/25538Wed, 22 Jul 2020 07:16:18 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:14:34 GMT]]>Seems like perfect troubleshooting conditions :)
ye so basically no response from the command. Only thing I can suggest is checking if the actual number is causing the "no response" by sending a different digit. is the modbus request going over the network or do you have a local mango instance there ?

]]>https://forum.mango-os.com/post/25537https://forum.mango-os.com/post/25537Wed, 22 Jul 2020 07:14:34 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:13:50 GMT]]>With a bloody big hammer.

]]>https://forum.mango-os.com/post/25536https://forum.mango-os.com/post/25536Wed, 22 Jul 2020 07:13:50 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:13:32 GMT]]>

although might actually currently be a timeout in the network, as it's on the top of a mountain in NZ. at the end of a Mimomax link :/
I do believe it's snowing up there currently..

@dan Sounds like I need to make a roadtrip! Haha

]]>https://forum.mango-os.com/post/25535https://forum.mango-os.com/post/25535Wed, 22 Jul 2020 07:13:32 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 07:08:10 GMT]]>Bugga, still same timeout message when network is responding better.

com.serotonin.modbus4j.exception.ModbusTransportException: java.net.SocketTimeoutException: connect timed out

If I interrogate a standard read point it works fine.

]]>https://forum.mango-os.com/post/25534https://forum.mango-os.com/post/25534Wed, 22 Jul 2020 07:08:10 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 06:57:06 GMT]]>although might actually currently be a timeout in the network, as it's on the top of a mountain in NZ. at the end of a Mimomax link :/
I do believe it's snowing up there currently..

]]>https://forum.mango-os.com/post/25533https://forum.mango-os.com/post/25533Wed, 22 Jul 2020 06:57:06 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 06:55:03 GMT]]>Interestingly I get a timeout message if I try writing the whole decimal number to either data point register.
0_1595402220586_b29f9048-0451-42d0-9ba5-23975e820734-image.png

If I change back to a hex value it just comes up with the top blue error again.

]]>https://forum.mango-os.com/post/25532https://forum.mango-os.com/post/25532Wed, 22 Jul 2020 06:55:03 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 06:46:25 GMT]]>Hey Guys, thanks again for helping out. That's a big number. I'll give that one a go, I'll try it into 4104 and 4103.

Cheers
Dan

]]>https://forum.mango-os.com/post/25531https://forum.mango-os.com/post/25531Wed, 22 Jul 2020 06:46:25 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 06:43:50 GMT]]>I think your answer is right here craig, something is amiss with how I did it, but looking at it now, I think we're all starting to break the back of it.

]]>https://forum.mango-os.com/post/25530https://forum.mango-os.com/post/25530Wed, 22 Jul 2020 06:43:50 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 06:23:55 GMT]]>Hi Dan

Regarding the address, I think you are correct. Well since other address work you are correct. If 4104 is not working I would try 4103.

I think @MattFox is correct regarding the ones's compliment that needs to be written to address 9. I get a different number tho.
0_1595400358409_Screenshot 2020-07-22 at 08.45.17.png

]]>https://forum.mango-os.com/post/25529https://forum.mango-os.com/post/25529Wed, 22 Jul 2020 06:23:55 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 02:55:01 GMT]]>It's greyed out and disabled.

]]>https://forum.mango-os.com/post/25528https://forum.mango-os.com/post/25528Wed, 22 Jul 2020 02:55:01 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Wed, 22 Jul 2020 02:53:47 GMT]]>@dan
just curious why the 'Number of registers' is '0'? shouldn't be at least '1'?

]]>https://forum.mango-os.com/post/25527https://forum.mango-os.com/post/25527Wed, 22 Jul 2020 02:53:47 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Tue, 21 Jul 2020 21:31:30 GMT]]>Interestingly, when I write the hex values I get this pop up error..
0_1595368403070_8b8aefed-818b-4048-850e-4e56afa9c2a3-image.png
Nothing written in the log during this time however :/
0_1595368421016_04c99fc6-f9b1-47b1-9109-ffaa4b0fe395-image.png

]]>https://forum.mango-os.com/post/25526https://forum.mango-os.com/post/25526Tue, 21 Jul 2020 21:31:30 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Tue, 21 Jul 2020 21:28:49 GMT]]>0_1595368234133_6f692b3b-5b32-4e53-8adc-08c5a7ab46a9-image.png
0_1595368250040_9530b480-46fd-4685-869a-41c8aebbf8c0-image.png

]]>https://forum.mango-os.com/post/25525https://forum.mango-os.com/post/25525Tue, 21 Jul 2020 21:28:49 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Tue, 21 Jul 2020 20:58:25 GMT]]>OK, now my brain is really hurting, I'll turn on the i/o log and see what mine is outputting.
Just to clarify a little further, the MODBUS register I need to write to is on 'Page 16', the manual says to multiply 256 x Page then add the Offset, so in this case I'm on (256 x 16) + 8 = 4104
When reading off battery voltages and other engine diagnostics off this the formula seems to work.
I'll try again with the decimal.

Cheers

]]>https://forum.mango-os.com/post/25524https://forum.mango-os.com/post/25524Tue, 21 Jul 2020 20:58:25 GMT<![CDATA[Reply to A Bit Stuck on Writing Multiple MODBUS Registers on Tue, 21 Jul 2020 20:21:47 GMT]]>Ok, so I can understand using 166774 gives you 0x00028b76, basically just bit shifts the entire thing in. And that by using a holding register implicitly puts a 4 in the front so only 104 is needed... But if the manual states you need a control key into 8 and its 1's complement into register 9, shouldn't it be 0x8B768B76 = 2339801974 DEC?

Fox

]]>https://forum.mango-os.com/post/25523https://forum.mango-os.com/post/25523Tue, 21 Jul 2020 20:21:47 GMT