Delta AS Series Programming Manual page 799

AS Ser ies Pro gra mm in g M anu al
Explanation
1. This instruction is for AS02HC-A only. This instruction is available for PLC with FW V1.08.or later and ISPSoft V3.10
or later.
2. Use this instruction with DHCCNT instruction. When executing DHCCNT instruction, the counting starts. And then you
can use DHCCMP instruction to do the comparison.
3. Before executing this instruction, you need to set up Cnt/Rev, Smpl and Avg. Once En is activated, the PLC scans
the values in Cnt/Rev, Smpl and Avg immediately.
4. You can edit the values in Cnt/Rev, Smpl and Avg during operation. Set new values and set the Update to ON. Once
the values are updated, the Update flag switches to OFF.
5. Module: The module number that is connected to the right side of PLC directly or connected to the remote module
that acts as PLC, e.g. the first connected module is module number 1, the second connected module is module number
2. Up to 32 modules can be connected and counted and each type of modules should be included in the count.
6. ChNo: Channel number for counter, channel 1 is number 1; channel 2 is number 2.
7. Cnt/Rev: Counted value of the encoder revolution for one time, ranging from 1 to 4294967295
(H'00000001~H'FFFFFFFF).
8. Smpl: Sampling cycle, ranging from 1 to 1000, unit: ms. Different values set in Smpl and Freq for output and RPM
_6
for output may cause different resolutions.
The start of sampling cycle and the current counted number (CurCnt) are two basic components for the calculation of
revolution. Therefore you need to take the following factors that may affect the measurement results into account.
Encoder Type
Incremental Encoder
SSI encoder
In Absolute Positon
6-520
： Error flag
Error
ErrCode ： Error code
Resolution of Frequency = 1000 ÷ Smpl (unit: Hz)
Resolution of RPM = 60000 ÷ �Smpl ×
Counter Type
The difference between the counted values in the same sampling
Ring counter
cycle exceeds the limit of 2
The difference between the counted values in the same sampling
Linear counter cycle exceeds the limit of 2
upper/lower limit.
Absolute The difference between the counted values in the same sampling
Positon cycle exceeds the limit of 2
The difference between the counted values in the same sampling
Ring Counter
cycle exceeds the limit of 2
Cnt
� (unit: rev/min)
Rev
Factors that affect the measurement results
31
.
31
or the counted value exceeds the
（ MT+ST Length ） -1
31
.
.