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122
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Modbus TCP connect failed
I tried to connect to my HMI by modbus TCP, but it threw a
System.IO.IOException: 'Unable to read data from the transport connection'
I previously connected to another HMI(BeiJer X2 base 7) using ...
Advice
0
votes
1
replies
51
views
Communicate PLC FX1N with Python
Can I communicate PLC FX1N with Python?
I have followed a tutorial on YouTube for FX3U using RS-485 and RS-422, but when I transmit data from Python to the PLC, it always fails. Is it because this ...
0
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0
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50
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How can I Properly Get Around Competing PORT Connections to Gather SQL Data?
I have one plotly-dash file, which collects data from a database that two other files are publishing to, one that collects data on power and the other on current. The two data collection files use ...
4
votes
1
answer
168
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Passing a pointer of a locally created array in C to a function different behave
I'm facing a super strange issue regarding passing a pointer of an array which is created locally inside a function to another function. This second function have to edit the same array.
So basically ...
0
votes
1
answer
166
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Install node-red-contrib-modbus fails
When I try to install the Node-RED package node-red-contrib-modus I am getting the following error:
2025年05月13日T13:00:55.767Z Install : node-red-contrib-modbus 5.43.0
2025年05月13日T13:00:55.884Z npm ...
-1
votes
1
answer
131
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Thingsboard.io How to send modbus write request from dashboard
I am trying to write some values into my modbus server with the dashboard of thingsboard (I am discovering it it is great).
I can read and display data without any issue.
I defined a setValue from my ...
1
vote
0
answers
53
views
Modbus TCP register returns unexpected value from EM Modbus Gateway IFS (Phoenix Contact)
I'm trying to read power consumption data (e.g., P_ALL, total active power) from a Phoenix Contact EMM 3-24DC/500AC-90-EXM-IFS device via a MODBUS-GATEWAY-IFS over Modbus TCP using Python (pymodbus).
...
1
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0
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81
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How to setup modem iRZ MC55iT | GPRS | Connection between PR200 and server
I have:
PC-server (Windows 10) with Java program
OWEN PR200 (ПР200, programmable relay)
GSM modem iRZ MC55iT
PC-client with installed Owen OPC Server and Scada
I need to make a two-side ...
0
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0
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79
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Can't connect properly to SHT20 RS485 sensor using QModBus or pySerial
I've been trying to connect to the RS485 sensor through various methods for a while now, but it doesn't seem to respond to any of the commands I send.
I've used this Python script and several serial ...
0
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0
answers
94
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Able to read data via modscan and using pymodbus on windows but not using pymodbus on rpi
I am using modbus RTU to read an MFM meter (WL4440 from LnT). I furst tested it using modscan and it is giving correct result :
Modscan result
However, when using pymodbus (on windows) I am getting ...
0
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0
answers
46
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Exception is thrown when I try to close the Modbus slave
I am using the j2mod Modbus library 3.1.1 with Java 8. In my JavaFX application, I created a wrapper class to handle the interaction with the Modbus slave instance. The wrapper class implements the ...
0
votes
0
answers
89
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Panasonic FPWINPro Structured Text For Modbus
I've got a FP-X C60R Panasonic PLC with a AFPX-COM5 module.
I have code that increments by 1 every second and it is working.
I'm trying to figure out how to send counter value to a modbus holding ...
1
vote
1
answer
105
views
Why does the Unaddressed Slave in Libmodbus library needs "Waiting for Confirmation" for Modbus RTU
Good day, everyone.
I'm trying to understand the behavior of Libmodbus library in C.
Here is the behavior of the Modbus RTU for the Addressed Slave and Unaddressed Slave.
When there's a request for ...
0
votes
2
answers
252
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Unable to read the full response coming over rs-485 from a Modbus device
I have been trying to communicate with a I-7000 IO module device that supports Modbus. In general I am able to successfully send commands such as writing to a coil or reading a coil but I face one ...
0
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0
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138
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PyModbus 0x05 Acknowledge Error (The slave has accepted the request and is processing it, but it takes a long time. The master should retry later.)
I'm trying to reach a modbus server and read registers. I know that it's possible because another software can read the values from the same IP, same Port and same registers. But when i try to read
...