FA417/418 high-speed suspended-spindle bobbiner is a new type of bobbiner developed in the recent years in China. It is markedly superior to supported-spindle bobbiner in spinning stability, consistency and quality acceptable rate. It is suitable for the pure-spinning or co-spinning of normal & combed cotton fiber and chemical fiber. It processes the drawn slivers into roves of different counts and twist numbers for spinning high-quality yarns. Compared with traditional bobbiners, this machine has canceled the differential mechanism, swinging mechanism, direction changing mechanism, shaping and cone speed variation, etc. It uses industrial control computer + PLC + inverter to realize synchronous control. It has canceled the change gears such as twist, lifting, coiling, tension, shaping angle, etc., and maintains only drawing change gear. This makes the mechanism simpler and improves the stability.

  In the whole system, the PLC, inverter and touch screen all achieve serial communication through RS-485. Siemens S7-200PLC has several communication modes including Freeport mode. Under this communication mode, the communication port is controlled completely by the user program, and the communication protocol is also set by the user. Under Freeport mode, the relation between PLC and the inverter is master slave relation. PLC is always at the master position. The data are transmitted and received in virtue of XMT and RCV commands. The formats of the commands are:
XMT: XMT TBL, PORT;
RCV: RCV TBL, PORT.

PORT is the communication port of PLC and TBL is the data storage region. The first bit of TBL is the length of the data to be transmitted. The first bit and the last bit of RCV command are the set starting bit and ending bit respectively.
Under Freeport mode, the communication port must be initialized before the communication command to set the communication speed, check bit, stop bit and communication mode, and to designate the special registers in communication aspect. These settings must be confirmed to be consistent to those of the inverter.

Starting bit + inverter number + command bit [+data+ [+check] and + ending bit
Among the above, those inside the [] are optional parts. Please confirm if the parameter settings need additional check and if the commands need data available.

The parameters are set through the man-machine interface to achieve the control to the Sanken vm05 series inverters and to achieve the following functions of the inverters:
1. Control function: operation, stopping, failure resetting, etc.
2. Monitoring function: frequency setting, frequency read-out, output voltage, current, etc.

 Note: In case that the program needs to be interrupted to verify if the commands are executed correctly or if the command for reading data requires, refer to Sanken vm05 manual and PLC manual for the details.