The work you commission OpenApps to complete is yours – never rented, never licensed – and always backed by a solid commitment to see projects through to the end.


OpenApps is a focused team of programming and design professionals who are committed to providing the best possible solutions for integrated systems – regardless of the challenge.


You can expect the same high level of quality, commmitment and dedication to your projects from start to finish – that’s a promise.


William (Bill) Rinear launched OpenApps in 2000 with a goal to help clients with whatever integration challenges were presented. “Open” to anything – we adopted a policy of complete transparency and project ownership for clients. Even today, the expectation is that the work and standard code (applications) produced by OpenApps remains open for client modification.


Machine-to-Machine Remote Monitoring that allows for more productive communication between the field device and your company’s service, sales and reorder points.


We will bring your legacy equipment up to current standards in technology, helping you save money in your manufacturing.


From concept to product and 100% simulated and tested.


10 years of experience with modernizing controls and with remote monitoring of natural gas compressors.


Systems for life cycle testing of products and light manufacturing applications.


CNG Controls - Compressor Monitoring

OpenApps customized a full OEM automation solution for controlling a CNG compressor using a Horner Automation XL7 controller and software that was tested using a real-world simulator for lower initial start time and start-up costs. view details

CNG Controls – Remote Compressors

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Retrofitting – Ice Manufacturing

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Retrofitting – Food Equipment

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Remote Monitoring – Lighting Controls

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Remote Monitoring – Water Tank

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OEM – Upgrade

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Thorough & quality work start to finish

Regular updates & communication about your projects

A dedicated manager who knows your project

Technical expertise & know-how

Excellent customer service & support

Projects completed on-time & done right

Projects completed on budget & to specification

Continued support to ensure proper operation

Non-commercial ownership of your commissioned projects & code



When developing a program in Proficy Machine Edition for PC or QuickPanel+, when do I decide to write a script or program in ladder logic?

There are many different options for programming in Proficy Machine Edition, each with their own unique advantages. Ladder Logic should be the go to option for writing control portion of the software. Ladder Logic tends to be easier to debug and operates more reliably than scripting.

Scripting is most useful when designing the HMI. In scripting the programmer can access CSV files, modify HMI objects, apply unit conversions, and change languages. Further, scripting comes in two varieties, ViewScipt and VBScript, and 3 different scopes. Good program management and proper planning of a project will include all of these options for a clean and well designed program.

I have problems communicating with Horner devices over Ethernet after setting up EGD communication protocols.

Horner’s EGD communication protocol seems to slow down CScape connection when enabled. This can be problematic when trying to debug programs from a remote location. Serial communications can provide a solid connection to the PLC but lacks the versatility of Ethernet. Consider using Modbus protocol for inter PLC communications over Ethernet. Later revisions of Horner’s firmware allow PLCs to be setup in the hardware configuration as both master and slave units.

I need to upgrade a Siemens TP177 HMI that is communicating to Allen Bradley SLC 5/03 over Data Highway. What do I need to do?

Siemens upgrade path from TP177 panels is to the TP700 Comfort panels. Siemens has decided to discontinue its Data Highway over RS422 protocol in this line of HMI panels and will not communicate using this method. There are two options to go from here, one can upgrade the Allen Bradley CPU to a SLC 5/05 with Ethernet or utilize the DF1 port on the SLC 5/03. If the latter option is chosen, Siemens provides an RS422/RS232 converter which will allow for communication.

Sometimes when removing SDCards from a Horner PLC I get file system errors on the card.

Removable memory has always come with this concern: how do I know data isn’t being written onto the card when I try and remove it. If the PLC (or any computer) is writing to SDCard when it is being removed, there is a chance for file corruption. To resolve this issue, computer developers have come up with the concept of “unmounting”. Unmounting will prevent the PLC from writing anything else from the SDCard, allowing it to be removed from the PLC safely. To as a Horner PLC to safely unmount an SDCard, Horner provides system registers %SR174 and %SR175 to unmount and check the status respectively.

When setting up multiple sequential screens in Horner, it’s easy to make mistakes and takes a long time to tag everything properly.

Horner PLCs allow for the HMI buttons to jump to a screen defined in a register. In the ladder logic, define two registers, one register can be setup one screen ahead of the current user screen (%SR1) and another register setup one screen behind. Buttons can then be copied and pasted to move between screens sequentially. The caveat to this is that it will break when trying to use Envision.