Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 55)

2 Functions of Devices in DVP-PLC
DVP-PLC Application Manual 2-27
2-phase AB input high-speed counter
Example:
LD X10
RST C251
LD X11
DCNT C251 K5
LD C251
OUT Y0
C251
Y0
X11
C251 K5 DCNT
C251 RST
X10
1. When X10 is On, RST instsruction will be executed. The PV in C251 will be cleared to “0” and the output contact
will be reset to be Off.
2. In C251, when X11 is On and C251 receives the A-phase signals from X0 and B-phase signals from X1, the PV
in the counter will count up (plus 1) or count down (minus 1). You can select different counting modes if you use
EH/EH2/SV series MPU.
3. When the counting of C251 reaches SV K5, the contact of C251 will be On. If there are still input signals coming
in, the counting will continue.
4. The counting modes (normal frequency, double frequency or 4 times frequency) of C251 (HHSC0) in ES/SA
series MPU can be set up by D1022. The default setting is double frequency mode.
5. C251 in EH/EH2/SV series MPU has external input signals to reset X2 and start X3.
6. The counting modes (normal frequency, double frequency, triple frequency or 4 times frequency) of C251
(HHSC0) in EH/EH2/SV series MPU can be set up by D1225. The default setting is double frequency mode.
7. The external input contact of reset signal of C246 (HHSC0) in EH/EH2/SV series MPU is disabled by M1264.
The external input contact of start signal is disabled by M1265.
8. The internal input contact of reset signal of C246 (HHSC0) in EH/EH2/SV series MPU is disabled by M1272.
The internal input contact of start signal is disabled by M1273.
ES/EX/SS and SA/SX/SC series MPU (double frequency)
0
1
2
3
4
5
X11
X10
6
3
0
1
2
3
4
5
A-phase X0
B-phase X1
PV in C251
Contact Y0, C251
Counting up Counting down
EH/EH2/SV series MPU (double frequency)