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Delta Electronics Programmable Logic Controller DVP-PLC User Manual

Page 302

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7 Application Instructions API 50-99

D V P - P L C A P P L I C AT I O N M A N U A L

7-18

Program Example 2:

1.

Use DHSZ instruction for high/low speed stop control. C251 is an A-B phase high speed counter and DHSZ only

performs comparison output when there is a C251 counting pulse input. Therefore, even when the present value

in the counter is 0, Y10 will not be On.

2.

When X10 = On, DHSZ will require that Y10 has to be On when the present value in the counter ≤ K2,000. To

solve this requirement, you can execute DZCPP instruction when the program was first RUN and compare

C251 with K2,000. When the present value in the counter ≤ K2,000, Y10 will be On. DZCPP instruction is a

pulse execution instruction and will only be executed once with Y10 being kept On.

3.

When the drive contact X10 = Off, Y10 ~ Y12 will be reset to Off.

X10

RST

C251

ZRST

Y10

Y12

M1000

DCNT

C251

K10000

X10

DZCPP K2000

K2400

C251

Y10

DHSZ

K2000

K2400

C251

Y10

4.

The timing diagram

2,000

2,400

0

X10

Y10

Y11

Y12

0

high speed

forward

low speed

forward

Stop

Speed of variable speed

transmission equipment

Present value in

counter C251

Program Example 3:

1.

Program Example 3 is only applicable to EH/EH2/SV series MPU.

2.

The multiple set values comparison mode: If D of DHSZ instruction designates a special auxiliary relay M1150,

the instruction will be able to compare (output) the present value in the high speed counter with many set

values.