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Hello, I'm looking at a small simple project with a Samba SM70-J. I'm running into quite an issue trying to figure out a modbus tcp connection. I'm able to see the device in modscan, and other PLC's as well. But I can't seem to get my configuration right in Visilogic. Would anyone happen to be available to help me troubleshoot this? The remote device is a Turck TBEN-S2-4IOL PLC is a Samba SM70-J with an ethernet adapter added. https://drive.google.com/file/d/1Zd_C7z2hyUnq0MS6XPUwR9KVwzaY_2A5/view?usp=sharing

Hi, I am pretty noob in Unitronics and Modbus, but I am trying my best to learn on the go. We have a V1210 with modbus configured and I am trying to read holding registers from there as I would like to get this data to my linux server every 1-2 seconds. I have tried to follow https://pymodbus.readthedocs.io/en/latest/source/client.html official documentation and create a .py for collecting the data. It seems that I am able to get the connection successfully and also my read request (modbus code 3) is sent successfully, but V1210 is responding with non-standard response, which is not recognised as Modbus protocol by my python client or Wireshark. I try to give all relevant information, but please ask more if my problem is not clear or detailed enough for giving answers. Modbus is working normally between this V1210 and other V1210:s we have with same connection details. I have tried to also use 40321 directly in the code, but it has the same results, and according to my understanding of pymodbus we should use 320. If anyone has example code of pymodbus client read holding registers towards V1210 I would appreciate a lot to receive it! My modbus config in V1210: Network ID: 255 Port 20257 Error I get: DEBUG:pymodbus.logging:Connection to Modbus server established. Socket ('IP of PLC', 59772) DEBUG:pymodbus.logging:Current transaction state - IDLE DEBUG:pymodbus.logging:Running transaction 1 DEBUG:pymodbus.logging:SEND: 0x0 0x1 0x0 0x0 0x0 0x6 0x0 0x3 0x9d 0x80 0x0 0x1 DEBUG:pymodbus.logging:New Transaction state "SENDING" DEBUG:pymodbus.logging:Changing transaction state from "SENDING" to "WAITING FOR REPLY" DEBUG:pymodbus.logging:Transaction failed. (Modbus Error: [Invalid Message] Incomplete message received, expected at least 8 bytes (6 received)) DEBUG:pymodbus.logging:Processing: DEBUG:pymodbus.logging:Getting transaction 1 DEBUG:pymodbus.logging:Changing transaction state from "PROCESSING REPLY" to "TRANSACTION_COMPLETE" Register Values: Modbus Error: [Input/Output] Modbus Error: [Invalid Message] Incomplete message received, expected at least 8 bytes (6 received) My python code: import logging from pymodbus.client import ModbusTcpClient from pymodbus.exceptions import ModbusIOException # Configure logging for pymodbus logging.basicConfig() log = logging.getLogger('pymodbus') log.setLevel(logging.DEBUG) # Unitronics Modbus TCP configuration details PLC_IP_ADDRESS = "IP of the PLC" PLC_PORT = 20257 UNIT_ID = 255 # Network ID TIMEOUT = 10 # Timeout in seconds (100 units of 10 ms each) RETRIES = 3 # Number of retries # Create a Modbus TCP client client = ModbusTcpClient(PLC_IP_ADDRESS, port=PLC_PORT, timeout=TIMEOUT, retries=RETRIES) # Connect to the PLC client.connect() # Reading holding registers corresponding to MI320 to MI322 START_ADDRESS = 320 # Start at MI320 (Modbus address 40321) REGISTER_COUNT = 3 # Read MI320 to MI322 (3 registers) try: # Read holding registers response = client.read_holding_registers(START_ADDRESS, REGISTER_COUNT, unit=UNIT_ID) # Check if response is an error if response.isError(): print("Error reading registers:", response) else: register_values = response.registers print("Register Values:", register_values) except ModbusIOException as e: print("Modbus IO error:", e) except Exception as e: print("General error:", e) finally: # Close the client connection client.close()

Good day. Try to connect to salve via MB TCP on T42 Modbus remote slave. Status = 3 (Fig.1); Periodic register read Status =11 ??? (Fig.2) And in Help I see Fig.3 What is wrong?

Hello, I am familiar with Modbus and have used it before from a vision slave PLC to a Unistream Master PLC. However, i now seem to be encountering issues when trying to communicate from one to the other. The Slave PLC is a V570-57-T20B-J with an V200-18-E1B Module and an Ethernet card added in being a V200-19-ET2. The Master PLC is a US5-B10-T24. Is there a special way I need to set up the ethernet card added into the Vision PLC as I have copied program logic used previously on already in built ethernet PLCs to get an Modbus communication error showing on the Unistream PLC, Status 3 on the Unilogic software, meaning there is communication but the commands arent set up correctly. And I cannot seem to figure out what is wrong with the Visilogic program. As seen in the attachments I have the code for visilogic with MI0 Flow Test value linked to the screen to be able to manually change the number to see it on the unilogic program. On the Unilogic program I am reading address 0. All IP addresses and ID numbers etc all are aligned as they should be. Any advice would be greatly appriciated.

Does anyone have experience with the BacNet gateway? I can't seem to establish a Modbus session from my V1210. PLC is connecting on port 502, socket 2(Client/Master) to the gateway's port 502, socket 9(Server/Slave). I've done a packet trace and found a Modbus/TCP error 'Cannot classify packet type' Attached is the tcpDump, Modbus comms config in visilogic, and gateway config file. Someone, please help!!! Thank you in advance tcpDump.pcap Modbus_BacNet.vlp Synthex BacNet Gateway Config.csv

Hello, I'm trying to use V700 as master and two lexium mdrive motors as clients through MODBUS/TCP. I set up the function blocks per example "V700_Modbus_TCP_master.vlp". I can get the motors to connect with V700 but once i write modbus commands to motors i get no motion. one of the examaples for requesting commad is mentioned below as modbus tcp commad for the motor to move at slew speed of 600000 micrsteps/sec. Please take a look at the code and let me know what i'm doing wrong. Also please let me know if you need more information. Thank you in advance for the response. Vertical Sandblaster.vlp

Hi I am trying to connect a 350 PLC with Inductive Automation's Ignition SCADA using Ignition's Modbus TCP driver. The PLC program image is attached. I do get a connection established in the Ignition software to the PLC but I can't read any tags. The following are all the settings I have in the Ignition SCADA I have tried Ignition's Modbus TCP, Ignition's Modbus RTU over TCP, Kepware's Modbus TCP driver all to no avail. I already have 2 other PLCs connected to the SCADA system via modbus TCP so I know that the Ignition's Modbus Drivers work. PLC program is also attached. Please advise. Kind Regards Rafe MOdbusTCP.vlp

Hi, I'm using a Samba 3.5 with ethernet card to send data to scada system. With test purposes I'm trying to send a discrete input MB 0 in response to the read digital input command (0x02) with the following instruction: But in the test software (Simply Modbus TCP Client) I can't see the value of MB0. Trying to find the answer, I tested sending the MI10 value in response to read holding registers command, but It doesn't work neither. I'm using the modbus TCP initial setup from the examples and the webinars, and I can see the connection in the Samba, but I can't send the data. I don't know if I'm missing something, this is my very first time with Unitronics modbus TCP. I really appreciate any help or suggestion to put me in the right way. Regards

Does anybody know if Vision controllers (ie V130) support Modbus TCP or do they support the Modbus RTU over TCP implementation. The difference is that the first follows the original Modbus TCP frames (ie no CRC) while the latter encapsulates the serial RTU framing sent over TCP media. Which one is supported by Vision and the other Unitronics controllers?

Hi! My name is Arnor and I am from Iceland I am trying to establish connection between two Vision PLC's. I have the master: V700 and V350 as slave. I can use SCADA pc software to connect to the slave and read the data. But I am not able to read data from slave to V700. I added both programs to google drive folder (sorry, the programs was to large, and its a bit mesh): https://drive.google.com/open?id=1yL1h1ZvJomBeoY7v22UvHVeY09T4ooAC I am using also Serial modbus on both sides that works well. The PLC are set up like this: V700: 192.168.1.20 V350: 192.168.1.30 Any idea what I am doing wrong? cheers!

Good day, Due to lack of ethernet sockets (v570) we need to set up modbus TCP communication with 2 Omron PLC's through the same socket. When connecting separately all works fine, but can't figure out principle to get them work together.. Tried different ways: after configuration, there is command to connect socket to one of PLC's IP (indirect IP and port), then after some time there is command to close socket and to connect to another IP. Nothing happens, conection to only one IP. Maybe something wrong with timing or connect socket commands. Maybe someone could share working example how to organize such connection that would be fast and robust. Thank you in advance. Happy hannukah

Hi, I have a problem with ethernet-connection, the PLC is V1040 with V200-19-ET1 -ethernet card. I've been using ethernet-connection with Samba (Modbus TCP connection to SCADA software) and it worked fine! The problem is, that when I plug ethernet cable from v1040 to ethernet switch, switch seems to have no activity. Not even Link/act -leds doesn't turn on. When I keep touch screen pressed and enter setup, it show MAC address and IP of ET1, so PLC recognizes that there's ethernet card installed. I've been trying another PLC and another V200-19-ET1, different ethernet switch, different cables, even straight connect to my laptop with cross-connected cable with no results. No activity in ethernet connection. What am I doing wrong? Does V1040 have jumpers that are needed to change?