Connecting to My Allen-Bradley PLC Without Using OPC Servers

Issue Details

I am trying to communicate with an Allen-Bradley PLC from my PC. However, I do not want to use NI OPC Servers or the Datalogging and Supervisory Control (DSC) Module. Do I have other options for connecting to my PLC?

Solution

Although LabVIEW DSC Module includes many tools to simplify communication with PLCs there are other ways to connect to your Allen-Bradley PLC without using OPC Servers or the LabVIEW DSC Module. The following options are available, given the Hardware supports it:

• Communication over EtherNet/IP using LabVIEW
• Communication over DeviceNet using LabVIEW and CompactRIO / PXI / PCI Hardware. 
• Communication over Modbus using LabVIEW 
• Direct serial communication

 

Additional Information

Ethernet/IP

The LabVIEW Driver for Ethernet/IP  is available for purchase, and supports using LabVIEW as an EtherNet/IP Class 1 Adapter (equivalent of slave). This driver can be used with an NI controller or from a computer connected directly to the PLC. This is a licensed driver, but its runtime-engine requires no license.

DeviceNet

Communication over DeviceNet requires the use of the PCI-8532, PXI-8532, or the NI 9882. For the full list of supported hardware and software, see the Related Links. 

Modbus

Modbus communication is possible on some, but not all, Allen-Bradley PLCs. Consult your product manual to see if Modbus communication is possible on your PLC. Modbus communication can be performed without the DSC Module using the LabVIEW Modbus API. The LabVIEW Modbus API is a free, as-is (unsupported) library. 

Serial

The manual for direct serial communication is available on the Allen-Bradley website.