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GSK218MC Series Machining Center CNC System PLC & Installation Connection Manual
6
Volume I
Programming
A
A
C
C
B
Fig. 2.1 (c)
(1) Relay circuit
Both Fig. 2.1 (b) and Fig. 2.1 (c) are shared a same operation. B and C are switched on after A
is turned on. B is cut off after C is ON.
(2) PLC program
A same relay is shared a same circuit, refer to the Fig. 2.1 (b); B and C are switched on after A
is turned on. B is cut off after one cycle of the PLC program is performed. In the Fig. 2.1 (c), C is ON
instead of B, after C is turned on.
2.2 Cycle Performance
PLC performs from the beginning to the end of the ladder diagram. It performs again from the
beginning of the ladder diagram after this diagram is performed, which is called cycle performance.
The performance time from the beginning to the end of the ladder diagram is abbreviated as a
period of a cycle treatment. The shorter of the treatment period is, the stronger of the response
capacity of the signal is.
2.3 Priority Sequence of the Execution (the 1
st
Level, the 2
nd
level)
GSK218MC Series PLC program are composed of two parts: the 1
st
level program and the 2
nd
level program, which are inconsistent with the performance period.
The 1
st
level program performs once each 8ms, which can be treated the short pulse signal
required for fast response.
The 2
nd
program performs once each 8*nms. N is the partition number of the 2
nd
level program.
PLC may divide the 2
nd
level program into N parts when the 2
nd
level program is executed. It is
performed one part for each 8ms.
