The dispensing system is a doctor who makes a diagnosis, prescribes a prescription, and the prescription is passed into the system. After the patient has paid, the system reorganizes the cans according to the type of drugs contained in the pharmacy, and then rolls them out onto a nearby shelf with a bar code affixed to the shelf. After the initial inspection of the system, the control stepper motor drives the toothed chain to rotate, and when the first layer of the peripheral bracket is detected, the stepper motor stops, and the servo motor drives the four-bar mechanism to push the drug shelf to the peripheral bracket, and the four-bar mechanism is withdrawn, and the drug dispensing system works. The stepping motor drives the gear belt to move, and the medicine box is arranged on the gear belt. After detecting the matching between the medicine box and the corresponding medicine tank, the lifting motor and the rotating motor move to complete the blanking of the first medicine. Then the second medicine is blanked, while the second medicine box is blanked for the first medicine. After the blanking is completed, the medicine box enters the weighing process. If it is within the tolerance range, it is packaged and labeled and sent to the patient. When the first patient's drug is dispensed, the second person's drug is also dispensed at the same time, the principle is the same.

The dispensing system is mainly composed of industrial computer, display screen, PLC, servo motor, weighing module, photoelectric sensor, displacement sensor, solenoid valve, relay, RTUMODBUS communication module, RFID and so on. PLC selected S7-200Smart as the monitoring core, with a variety of functional modules and human machine interface (HMI) to choose from. The S7-200Smart supports TCP/TP and modbus communication, and the system configuration is reasonable and the technology is feasible, which can fully meet the field requirements. This part mainly controls the action of the relevant motor according to the state of various sensors.

The PLC control cabinet is equipped with S7-200Smart, 485 communication module, IO expansion module, RTU controller, wiring terminals, switching power supply, relay. The touch screen is installed on the door panel of the PLC control cabinet, which greatly facilitates the user's operation and real-time monitoring of the equipment status. Through the touch screen can be a good observation of the state of dispensing and the operation of each motor, but also can set parameters and view the corresponding alarm information.

Various sensors All kinds of sensors collect physical signals in real time, output standard 4~20mA current signals, and with two-wire RVVP cable separately transmitted to the PLC control cabinet. Each sensor includes photoelectric sensor, weighing sensor and so on. The photoelectric sensor is used to detect the alignment between the movable bracket and the peripheral bracket. Each layer of the peripheral bracket is provided with photoelectric sensors. The weighing module is used to detect the weight of the cartridge after dispensing, analyze the system error, and place it in front of the packaging mechanism.

RFID technology Each medicine can is equipped with an electronic tag for reader identification. The reader communicates with the PLC via RS232 to RS485, and transmits the data to the system. Siemens reader RF260R is adopted.

The core of the efficient drug taking system of TCM granules is that each flavor of each prescription can accurately fall into the medicine box. The closed-loop control is done to improve the accuracy of the system. The device adopts a double closed-loop control system, which is an encoder to detect the rotation Angle of the servo motor and a weighing module to detect the weight of the cartridge. The servo control system uses the position control method and the encoder position feedback to form an internal closed-loop system in the servo drive, which improves the operating accuracy of the equipment." The main reason for adopting an external closed-loop control system is that when the rotation Angle of the servo motor does not reach the weight of the dosage, the precision of dispensing will be affected. Increasing the detection of the weighing module can solve this problem well, and the stability and rapid response of the equipment can be improved through PID regulation.

The operation procedure, the equipment is powered on and started, and the operation status of each motor and the status of related sensors, indicators and communication modules are detected. If something goes wrong, manual repair. Then test the weight of each medicine box, if it is less than half of the medicine box content, then the medicine box is added, and then the medicine box arrives on the medicine tray. When the prescription arrives in the system, the system acknowledges receipt of the prescription, then compares the drugs in each shelf in turn, selects the shelf with the highest coincidence, rotates to the designated position, and replaces the other drugs in the prescription to the shelf. Then, it is pushed by the push-out mechanism to the peripheral bracket to prepare for dispensing. When the medicine box is detected in the peripheral bracket, the servo motor drives the toothed belt to form an accurate displacement, and the rotary motor drives the medicine mouth up and down. The medicine box weight is tested after the medicine is finished. If the medicine box meets the standard, the next batch of preparation is carried out until the preparation is finished. If it is not up to standard, the micro-rotation Angle is formed again through PID adjustment until the drug is up to standard. When the drug is dosed, the label is sealed and delivered to the patient.