I'm trying to read six input registers from a remote device but the software I put together doesn't seem to do much; no errors but no read-backs either. I'm a beginner, so the answer is probably simple. The remote device input registers start at 200 hex. The device uses TCP and the IP address is correct. My computer communicates well with the remote device through QmodMaster. Any help you could give would be appreciated. Thanks, Mike.
Modbus Read 01.pdf So far 01.vi
This package contains the Plasmionique Modbus Master library for LabVIEW.
It supports RTU, ASCII and TCP modes with the following function codes:
0x01 - Read Coils
0x02 - Read Discrete Inputs
0x03 - Read Holding Registers
0x04 - Read Input Registers
0x05 - Write Single Coil
0x06 - Write Single Register
0x07 - Read Exception Status
0x0F - Write Multiple Coils
0x10 - Write Multiple Registers
0x16 - Mask Write Register
0x17 - Read/Write Multiple Registers
0x2B/0x0E - Read Device Identification
Other features include:
- Sharing a COM port across multiple Modbus sessions using VISA locks (10 second timeout).
- Sharing a Modbus session across multiple communication loops.
- TCP transaction ID handling to ensure that requests and responses are matched up correctly in case responses are received out of order.
- Modbus Comm Tester, available through the "Tools->Plasmionique" menu, for testing communication with a slave device without writing any code.
- Detailed help document available through the "Help->Plasmionique" menu.
Examples are included in "<LabVIEW>\examples\Plasmionique\MB Master\":
MB_Master Comm Tester.vi: Demonstrates usage of API to open/close connection and communicate with a Modbus slave device. MB_Master Multiple Sessions.vi: Demonstrates usage of API to open concurrent Modbus sessions. MB_Master Simple Serial.vi: Demonstrates polling of a single input register over serial line. Download a copy of the user guide here: MB_Master - User Guide.pdf
Note that Version 1.3.4 of this library has been certified compatible with LabVIEW and has been released on the LabVIEW Tools Network: http://sine.ni.com/nips/cds/view/p/lang/en/nid/214230
The most recent version of this library will always be released on LAVA first before going through NI's certification process.
***This project is now available on GitHub: https://github.com/rfporter/Modbus-Master
I wanted to cross post metux's discovery here asap, and have a separate discussion.
Metux's original post:
The recent Linux driver package introduces a CRITICAL security vulnerability:
It adds additional yum/zypper repos, but explicitly disabling package signing and using unencrypted HTTP transport. That way, it's pretty trivial to completely takeover the affected systems, by injecting malicious packages.
DO NOT INSTALL THIS BROKEN SOFTWARE - IT IS DANGEROUS !
CERT and BSI are already notified.