229
CHAPTER 11 TROUBLESHOOTING
11
11.5 T
roub
leshooting for
E
a
ch Pheno
menon
11.5.1
Whe
n the setting
on the oper
ation mode setting is the no
rmal mode
●
How to fix pulse form
This portion describes how to fix pulse waveform by dummy resistance that can be used against noises from outside or
distortion of pulse waveform.
To fix pulse waveform effectively, increase load current inside cables by applying dummy resistance of several hundreds
ohms (/several W) between the pulse input terminals connected to the encoder. The greater the load current, the more
effective this method is.
●
Effect
• When the distance between the encoder and the high-speed counter module is long
Distortion of waveform is fixed and the pulse waveform becomes stable.
• When the pulse waveform is distorted due to noises from outside
Taking the method above stabilizes pulse waveform; distortion of pulse waveform by noise can be reduced.
●
Example of dummy resistance at 24VDC
●
How to choose dummy resistance
The following example describes how to choose the required resistance amount and rated-standard electricity of dummy
resistance.
<Example>
• How to calculate the dummy resistance amount (at 24VDC)
Calculation: R = V
÷
I = 24V
÷
35mA = 680
Ω
• How to calculate rated-standard electricity (at 24VDC)
Calculation: P
1
= V × I = 24V × 35mA = 0.84W (approximately 1W)
Calculation including a margin: P
2
= P
1
× 2 = 0.84 × 2 = 1.68W (approximately 2W)
Result: Install dummy resistance of 680
Ω
(/2W) in between the pulse input terminals.
Does the input pulse waveform meet the performance
specifications?
Check the pulse waveform with a synchronoscope. If the input pulse does not
meet the performance specifications, input pulses which meet the performance
specifications.
Does the other channel show the same count result
when the same input is applied to the other channel?
If a different count value appears, a module failure may be the cause. Please
consult your local Mitsubishi representative.
Check item
Action
4.1k
270
240
820
DIF
5V
24V
COM
High-speed counter module
Phase A
Phase B
B19(B13)
A20(A14)
B20(B14)
A19(A13)
4.1k
270
240
820
DIF
5V
24V
COM
B17(B11)
A18(A12)
B18(B12)
A17(A11)
Shielded twisted pair cable
24V
OUT
24V
OUT
E
Put dummy resistance of several
hundreds ohms (/several W)
between the pulse input terminals,
24V and COM.
Содержание NZ2GFCF-D62PD2
Страница 1: ......
Страница 2: ......
Страница 54: ...52 Memo ...
Страница 206: ...204 Memo ...
Страница 303: ......
Страница 304: ......