Case study 2, GlaxoSmithKline syringe tower
After undertaking a number of successful projects for the customer Challenge Electronics was asked to design and manufacture a complex test machine for GlaxoSmithKline called the syringe drive tower. The purpose of this machine was to mix precise quantities of different substances at precise delivery rates and precise timings, all under the control of a PC. Each machine held 8 syringes but to expand the system up to 16 machines could be controlled together using the RS485 serial communications system.
The substances to be mixed were loaded into 8 disposable syringes in the machine under control of the PC. Then at the exact times controlled by the PC the tap on the outlet of each of the syringes was individually opened and the contents expelled by an independent stepper motor drive system for each syringe.
Challenge Electronics was commissioned with the following tasks:
- Source stepper motors, lead-screws and nuts for the syringe drive mechanism.
- Source geared motor and drive-train for tap control.
- Design all metal components of the structure and drive mechanisms.
- Design electronics to communicate with PC under RS485.
- Design electronics to drive stepper motors and tap motors.
- Design embedded controllers to manage each individual syringe.
- Write microprocessor programs for embedded controllers and communication controller.
- Design control PCB.
- Design Facia overlay.
- Produce production, test and repair documentation.
- Source components and metalwork.
- Manufacture 8 systems.