Modbus function code 03 and 04 confusion
By Harvard on 2 December, 2016 - 12:06 pm
Function Code 4 is used to read analog inputs that come from an analog to digital converter and...
Modicon Quantum/Word Mapping
Trying to understand word mapping
Citect v7.40 SP2 - Modbus/TCP - Request Wrong Word Count
Citect is sending wrong Modbus requests to my Moxa gateway. Word count is bigger than it should be - 7A HEX instead of 2.
Citect v7.40 SP1 - PM710 meter - FloatMode problem
Posted by agoslinski on 10 June, 2016 - 4:05 am
I have a problem with reading values from energy meter PM710 (Citect - Modnet - PM710)
Modbus Errors in HVAC System - Invalid CRC and Response Not from Requested Slave
Modbus errors after connecting heat pump to HVAC, Invalid CRC, Operation times out, Response not from requested slave.
By Harvard on 3 November, 2016 - 10:55 am
Assuming this is 1/2 duplex set up, the slave (address 8) may be responding too soon. If so,...
Want to communicate between controller and MATLAB via Ethernet cable using Modbus over Ethernet
By Ikhtiander on 2 November, 2016 - 10:09 pm
Hello reza_Hdr, Matlab has no ready to use Modbus instruction in its library but it is possible...
transfering chunk data with Modbus protocol
I want to transfer chunk data (e.g. 64KByte) with Modbus (RTU). But I have not found corresponding function code. What should I do?
By Brain Dade on 30 October, 2016 - 12:36 pm
In Modbus serial (not 485) the max chunk you could send reliably is 1024 bytes, the max Modbus...
best practice to secure modbus TCP
By smachin on 20 October, 2016 - 12:02 pm
Did anyone ever come up with a good solution to securing Modbus TCP devices? I am working on...
Confusion about using Modbus to read the status of discrete inputs
Floboss 107 to DCS Analog Input
Floboss 107 to DCS ABB Bailey Analog Input
How to connect 10 RS-485 Devices with Citect SCADA
How can I implement a SCADA system for 10 devices that communicate via RS-485?
By icp-robert on 30 September, 2016 - 2:30 pm
I am assuming that your SCADA is running on a PC. RS-485 allows you to Daisy chain devices; so you...
By Patrick Lansdorf on 30 September, 2016 - 3:31 am
Hi Amer, Normally, you will need a gateway (Modbus RTU to Modbus TCP), where the Scada will be...
Mitsubishi UPS 9900b Modbus Registers
Integrate Mitsubishi UPS 9900b with Niagara AX
By Bob Peterson on 28 September, 2016 - 10:23 pm
Just an educated guess but I think the ex is supposed to indicate that it can be either a five or...
HINET Modbus DDE SERVER 2014
HINET ModBus DDE SERVER 2014,
By Dave Hunt on 12 September, 2016 - 4:31 pm
I will be testing your DDE server with our FIN Data Collection server which still uses good ole...
Reading Target Register Using ModBus on Promass F83
Querying the ModBus Promass F83 Register using 04 Function code.
By Harvard07 on 5 September, 2016 - 10:48 am
> Thanks! 100% success with 2016 to 2017. But the question is why? Normally the documentation...
ALSTOM Flakt Bus to Modbus HELP
Need some help, does anyone know Flakt bus? is there any gateway or converter to Modbus or any other protocol?
By Rakesh on 2 September, 2016 - 8:07 am
Hi Martin, Flakt Bus- this topic to new to me. can you share more details? FYI, we are working...
Modbus TCP and SNMP to SQL DB
Looking for a small app to capture CT sensor Data...
By Armin Steinhoff on 30 August, 2016 - 9:25 am
Hello, > I would like a small (but important) backend application that I can > run that...
By Mark on 29 August, 2016 - 10:50 pm
Hello, PeakHMI can read/write MODBUS, SNMP and log to any database (SQL) via ODBC driver (all...
By James Ingraham on 29 August, 2016 - 5:36 pm
> I would like a small (but important) backend application that I can > run that will allow...
Character String and Flags from Same Master in S7-1200 PLC Modbus Communication
Siemens S7-1200 PLC Modbus RTU with CM1241-RS232
Centum 3000 Talks Modbus TCP?
Polling data from Centum CS 3000 using modbus TCP.
Modbus Communication Between ControlLogix5570 and Mark VIe
Can I use Modbus communication with controllogix5570, directly or should use prosoft products?
Multi-circuit 3 phase Energy Metering Alternatives
Measuring 50+ 3 phase circuits. Instead discrete meters, want to use multi-circuit product or Data Acquisition modules and software.
Modbus RTU over ethernet data loss
Modbus RTU over ethernet data loss.
By Dona Rosado on 13 July, 2016 - 8:18 am
Hello Mark, Yesterday we did a lot of tests and we found out that, We need to do various request...
By Mark on 12 July, 2016 - 6:12 pm
Hello, Depending on the RTU driver some drivers are time based. The original MODBUS...
By Dona Rosado on 12 July, 2016 - 2:59 pm
Hello Mark, Yes, I got your point. It seems we are asking and expecting N bytes and assuming...
By Mark on 12 July, 2016 - 10:48 am
Hello, I would expect it more as a coding problem on the receiver. Depending on the TCP/IP code;...
By Dona Rosado on 11 July, 2016 - 5:28 pm
Hello! We are having the same problem. We have a RTU device connected to a serial/ethernet...
Ifix 5.8 Poll Data from MBE Driver Unable to Update Database
Ifix 5.8 database cannot poll data from MBE driver that shares the same Modbus Ethernet data source
By DnA on 30 June, 2016 - 5:11 pm
Node name shouldn't matter here I think. MBE driver polls the modbus unit at the slower rate even...
Modbus C or assembler source code for microcontroller
I am working actually with protocol modbus and microcontroller AT89c52.
looking for java modbus library
By SM on 15 June, 2016 - 12:59 pm
I have installed this but how do I test this, is there any documentation? >jamod is mostly...
Accesing the Modbus Device from Internet without VPN Connection
Posted by Heru Iqbal on 1 June, 2016 - 1:51 pm
Software for accessing a Modbus device on a local network without a VPN Server.
By Heru Iqbbal on 8 June, 2016 - 11:31 pm
Thank you so much Mr. James Ingraham for your opinions.. I agree with your opinion.. But.....
By James Ingraham on 8 June, 2016 - 2:34 pm
Some things I will not be doing on production equipment: - Download a RAR file from someone's...
By Heru Iqbal on 8 June, 2016 - 11:47 am
Thanks for your question Mr. David_2 HINET is short of Heru Iqbal Network Enterprise...