GSK 980TC3 Series, Manual

Page: 55 / 226

Chapter 5 PLC Functional Code
43
Ⅰ
Programming
The system will check the sequence number of the rising edge automatically, when the number
exceeds the range or the number is duplicated, an alarm occurs.
5.22 DIFD
（
Falling Edge Check
）
Function:
The DIFD instruction set the output signal to 1 for one scanning period on a falling edge of the
input signal.
Format:
DIFD
ACT
L
falling edge （
W
）
Fig. 5-22-1
Control conditions:
Input signal: on a falling edge
（
1 Š 0
）
of the input signal, the output signal is set to 1.
Output signal: the output signal level remains at 1 for one scanning period of the ladder level
where this functional instruction is operating.
Parameter:
L
：
rising edge number, range 0~255. Another DIFU instruction or DIFD instruction in
the ladder uses the same number, the system will alarm.
Operation
A C T
O U T
1 2 3 4
E xecution
period
Fig. 5-22-2
The system checks the sequence number of the falling edge automatically, when the number
exceeds the range or the number is duplicated, alarm occurs.
5.23 COMP
（
Binary Comparison
）
Function:
Compares binary values. Specifies enough byte to store the input data and the comparison data in
the memory.
Format: