Project: Biopharmaceutical filtration automation, August 16, 2005

By Control Engineering Staff August 16, 2005

We expected to be working on the HMI this past week. Unfortunately, the workstations on which we were to develop have not arrived because the customer and skid builder are still working out the details of the hardware that will be used as workstations. While our San Francisco office is doing most of the development, our home office in Tinley Park, IL, has much more company owned hardware on which we can develop. So to keep the project moving forward, Tinley Park resources have developed static graphic displays. Static displays include the basic process equipment layout, piping connections, and device dynamos that are configured for specific device tags but have not been verified because they are not developed against a PLC controller with the proper control module software. We currently plan to provide seven graphic displays:

1. Recovery overview;
2. Harvest vessel;
3. Micro filtration skid;
4. Ultra filtration vessel;
5. Ultra filtration skid;
6. Filtrate hold vessel; and
7. Control system network status.

Using graphic building blocks from our internally developed iFix graphics library (tanks, pipes, and iFix dynamos) we have created individual graphic files for all but the control system network status display.

The diamond shaped satellites near the various devices are part of a single grouped object that references the control module that interfaces with the device. For example, a valve includes the valve itself, a mode satellite (auto or manual mode), an interlock satellite, and a batch hold status satellite. To add a valve to the graphic, a user drags a valve from the library and drops it on the graphic at the desired location. After dropping the valve on the graphic, a dialog pops up where the user may type in the appropriate control module tag. After clicking OK on the dynamo form, all of the dynamic portions of the valve are linked via OPC to the proper parameters in the PLC.

The iFix dynamo feature has helped to reduce graphic development time at least by 50% when compared to editing each dynamic property of each graphic device.

Currently, the PLC code is loaded into a development ControlLogix PLC in San Francisco while the graphic files are created on workstations in Tinley Park, IL. The graphics in Tinley Park are not connected to the PLC controller in San Francisco but we may see if we can do this to allow us to debug the graphics until the workstations arrive.

As we move forward in the project, receiving the workstations will be essential to moving forward. Developing complex sequences and recipes is extremely difficult and slow without the aid of a fully functional HMI system. As for exactly what happens next, that’s hard to say without the workstations. Check back with us next week to see how things turn out.