From PLC control to integrated solutions
The sampling and transport system is controlled from a dedicated PLC interfaced to the QCX computer via serial or network links. The PLC system takes care of the device control, interlocking and acquisition of detailed status and alarm signals for all connected equipment units. Typical control system specifications are illustrated in diagram on top of opposite page. The applied advanced high level PLC programming techniques ("QCXSYS") ensures time efficient PLC software engineering for the specific project as well as a very high quality and consistency in the logic control of all devices. The QCX/AutoSampling module controls the timing of automatic routine sampling and identifies the samples based on sampling point, product type and time of sampling. Facilities include parameter set-up, automatic sample calls on a time or production quantity basis, on-demand sample calls and mimic diagrams for supervision of all activities in the sampling and sample transport system. Face plates enabled by right clicks in the mimic diagrams provides operation and diagnostic details of the PLC control (face plates supported only, if the PLC control software is based on "QCXSYS" programming techniques). In according with individual sample priorities and wait list status, samples are sent from the process stations to receive/send stations in the laboratory, where the sample cartridges are emptied and returned to the relevant process station.
In many projects QCX/AutoSampling is one functional block in a large automatic configuration incorporating also QCX/AutoPrep or QCX/RoboLab. In these cases entities like sample ID, sampling time etc. are automatically passed on to fully support automated operation. Where relevant these software modules have convenient integration links between them. One example is integrated priority handling: in case an equipment error leads to reduced capacity in the automated laboratory it is possible to automatically scale down the sampling activity, so that either low priority samples are not called for or a group of samples are called less frequently.
