5 Common Questions about PLC-5 Conversions

BCI 5 Common Questions about PLC5 Conversions

While Allen-Bradley PLC-5 controllers are obsolete, there are still many systems out there running on that hardware. We have completed dozens of conversions to AB ControlLogix PLCs and with other PLC conversions. Here are the most common questions that we receive.

Does BCI Use Conversion Software?

We do not. We’ve done some testing with the conversion software available, and we find that we need to retouch large portions of the programming that didn’t convert completely. So we find it more reliable and less time consuming to rewrite the programming from the start. In addition, we have new, standardized logic that is more solid and more reliable. Since we rewrite using our standards, it makes commissioning in the field faster as well. Our engineers are very familiar with our standard of code, so they are easily able to find anything they are looking for to troubleshoot.

What Kind of Downtime Should We Expect?

It depends on the size of the system, but we have gotten pretty proficient at completing the installations over a weekend of scheduled downtime. Depending on the size of the project, we may send extra engineers out to the site for the installation. Sometimes, if both the PLC and the field devices are being upgraded, we can split the project over two weekends: one for the PLC installation and the other for the field device commissioning. Ideally, we prefer to do the entire conversion at once, but we understand the constraints that some facilities are under and we try to work with you as best we can.

What Kind of Support Will We Have?

Bachelor Controls stays on site through all of the testing and check out before start up. Then, we often stay on site for a couple of days to ensure that the system is running well.

More importantly, we involve our clients upfront with our Factory Acceptance Testing (FAT). We invite our clients to come to the test at our offices. At the FAT, we simulate as much as possible and welcome the clients to try out the software ahead of the installation. Ensuring that all the software bugs are worked out, when we arrive on site, we are only left with possible mechanical issues. We very much prefer that our clients are heavily involved in this FAT so that issues or changes are revealed when they are not causing downtime.

If we convert the PLC-5, what else will need to be converted?

It depends on your system. However, one advantage of using an experienced control system integrator like Bachelor Controls is that we know which questions to ask to make sure we have a full understanding of the scope of the project before we get started. One problem that we have seen in the past is when facilities hire less experienced programmers, they might not anticipate all of the pieces of the project until it delays the project or blows the budget. This is one of the reasons why BCI is the best value through start up.

That said, common components that may need to be converted include:

  • Your HMI platform, whether it’s Wonderware, AB FactoryTalk, or FactoryTalk Batch.
  • You also have to be careful about any VB applications or SQL databases that may be communicating with the PLC. The drivers may be outdated and may cause serious problems if that is not addressed up front.
  • Field devices such as scale controllers and flow meters.

Can you give me an example of a recent conversion project you have completed?

We’ll give you three!

  • A flavoring production facility needed 3 PLCs converted and 2 were on one line. First we replaced the PLCs, leaving the old 1771 IO in places. The drives communicated over remote IO and DeviceNet. Later, we came back and swapped out to the more modern 1756 IO.
  • At an extrusion facility, we converted from a PLC-5 to a CLX. In that case, we were able to use a conversion backplate, which meant we were able to leave most of the cabinet as is, instead of doing major rewiring.
  • Another food production facility was running on a Quantum PLC and wanted to convert to the Allen Bradley CLX. We also completed that project in two phases; first communicating to the original Quantum IO modules, then returning to convert the IO.

To discuss your upcoming PLC-5 conversion project, Contact Us.

Bachelor Controls