Case Studies

Rockwell RSLogix 5000 Add-on Instruction Programming for Herma 400c Labeler

Posted in Allen Bradley PLC, Manufacturing Automation and Intelligence, PLC Programming


DMC created a fully functional Rockwell RSLogix 5000 add-on instruction suite for communicating with the Herma 400c labeling unit. The add-on instructions allowed for a modular communication method that controlled the labeler and read its status feedback, using both a set of digital IO and a more complex RS 485 configuration option. The client intended to integrate the labeler into several future machines, so the end result needed to be easily portable without any project-specific dependencies built into the code.


DMC was hired by the OEM to assist in creating PLC code to communicate with a Herma labeling unit on their production line. The customer was quite familiar with integrating labeling units into their machines, but did not have code in place to communicate with this particular unit’s RS 485 protocol. DMC communicated with both the customer and the labeler manufacturer to determine both project requirements and technical capabilities of the labeling unit. DMC then implemented a reusable and intuitive RSLogix 5000 add-on instruction for easier RS 485 communication to the unit. Complete testing with hardware was performed at the client’s facility to both verify correct functionality and train the client on proper use of the tool.

Complete, independent source code was delivered to the client and the client will not require DMC’s aid when implementing this solution on future projects

Customer Benefits

  • Successful implementation of reusable code to communicate with Herma 400c labeling units
  • Complete verification checks performed by DMC at customer facility
  • Code created as modularly as possible to increase reusability on future projects


  • Rockwell RSLogix 5000
  • Rockwell RSLogix 5000 add-on instructions
  • Rockwell CompactLogix PLC
  • Herma 400c Labeling Unit