GSK 218M, Руководство по подключению и программированию PLC

Страница: 19 / 227

GSK218M CNC System Connection and PLC Manual
16
(1) Relay circuit
In Fig. (A) and (B), the operations are the same. Turning on A turns on B and C. Turning on C
turns off B.
(2) 218M PLC program
In Fig.(B), as in the relay circuit, turning on A turns on B and C, and after one cycle of the PLC
sequence, turns off B. But in Fig.(C), turning on A turns on C, but does not turn on B.
2.2 Repetitive cycel
The sequence program is executed from the beginning of coding to the end of coding of the ladder
diagram in the sequence written. When the seqeuence program ends, the program starts over
form the beginning. This is called repetitive operation.
The execution time from the beginning to the end of the ladder diagram is called the sequence
processing time. The shorter the process time is, the better the signal response becomes.
2.3 Priority of execution(1
st
level, and 2
nd
level)
GSK218M PLC consists of two parts: 1
st
level sequence part, 2
nd
level sequence part. They have
different execution period.
The 1
st
level sequence part operates every 4ms, which can operate the short pulse signal with
high-speed response).
The 2
nd
level sequence part operates every 4*n ms. Here n is a dividing number for the 2
nd
level
sequence part. The 2
nd
level sequence part is divided into n part, and every part is executed every
4ms.