Reading the ModBus bus with the Patron

Vesa Kauppinen

Hi,

I have tested to read the Kamstrup 803 meter on the Patron M527 via Modbus.

However, I don't get any results from mbpoll.

root@M527-sn60:~# mbpoll /dev/extcomm/0/1 -m rtu -P none -d 8 -s 1 -b 19200 -a 44
mbpoll 1.4-12 - FieldTalk(tm) Modbus(R) Master Simulator
Copyright © 2015-2019 Pascal JEAN, https://github.com/epsilonrt/mbpoll
This program comes with ABSOLUTELY NO WARRANTY.
This is free software, and you are welcome to redistribute it
under certain conditions; type 'mbpoll -w' for details.

Protocol configuration: Modbus RTU
Slave configuration...: address = [44]
                        start reference = 1, count = 1
Communication.........: /dev/extcomm/0/1,      19200-8N1 
                        t/o 1.00 s, poll rate 1000 ms
Data type.............: 16-bit register, output (holding) register table

-- Polling slave 44... Ctrl-C to stop)
Read output (holding) register failed: Connection timed out
-- Polling slave 44... Ctrl-C to stop)
Read output (holding) register failed: Connection timed out
-- Polling slave 44... Ctrl-C to stop)
Read output (holding) register failed: Connection timed out

Same result on mbpoll /dev/extcomm/0/0 -m rtu -P none -d 8 -s 1 -b 19200 -a 44

Br,
Vesa

AVsetula

Hello Vesa,

Only some Patron ports are available using the deprecated /dev/extcomm/Y/X notation.
I recommend using the ports from the table in this article: Patron serial port mapping

To verify communication with all our Modbus devices, I recommend asking the holding register 1003, which is available for all Modbus devices Unipi and whith contains a unique identifier, according to which the device can also be recognized.

Best regards,
Antonin

Vesa Kauppinen

Hi,

How can i ask the holding register 1003 with mbpoll?

@AVsetula said in Reading the ModBus bus with the Patron:

To verify communication with all our Modbus devices, I recommend asking the holding register 1003, which is available for all Modbus devices Unipi and whith contains a unique identifier, according to which the device can also be recognized.

Thank you!

/Vesa

AVsetula

Hi @Vesa-Kauppinen,

From Unipi Patron I/O boards by:

Section 1: mbpoll -m tcp 127.0.0.1 -a 0 -0 -1 -r 1003 -p 502
Section 2: mbpoll -m tcp 127.0.0.1 -a 0 -0 -1 -r 1103 -p 502
Section 3: mbpoll -m tcp 127.0.0.1 -a 0 -0 -1 -r 1203 -p 502

And from Unipi Extension using ttyNS0 port:

mbpoll -m rtu /dev/ttyNS0 -b 19200 -P none -0 -1 -r 1003 -a 15

Best regards,
Antonin