Hitachi IJ RX2 Technical Manual page 48

Example 2: Calculate the diameter ratio (RT) of the pulley when the rotary encoder is connected to the
<Calculation conditions>
Example 3: Calculate the necessary rotary encoder resolution when a pulley is installed to the shaft of the
<Calculation conditions>
7)
4-17 ●Input/output (I/O) specifications
conveyer through a pair of pulleys.
Conveyer
Pulley B
Pulley A
Encoder
●Dot font
●Inter-character space
●Inter-character interval
●Diameter of conveyer pulley : 60mm
●Resolution of rotary encoder : 1,000PPR
Amount of movement of conveyer per 1 revolution of rotary encoder
1
60mm 3.14=188.4mm/rev
×
2
Number of scans which must be executed while conveyer moves 1mm
6 scans/1.8mm=3.33 scans/mm
3
Necessary number of output pulses (resolution) from rotary encoder
188.4mm/rev 3.33 scans/mm=628PPR
×
4
Diameter ratio (RT) of pulley
RT=Diameter of pulley B/diameter of pulley A=1,000PPR/628PPR=Approx. 1.6/1
rotary encoder and this pulley is connected to the conveyer.
Diameter
Conveyer
Encoder
●Dot font
●Inter-character space
●Inter-character interval
Amount of movement of conveyer per 1 revolution of rotary encoder
1
95.5mm 3.14=300mm/rev
×
2
Number of scans which must be executed while the conveyer is moving 1mm
6 scans/1.8mm=3.33 scans/mm
3 Necessary number of output pulses (resolution) from rotary encoder
300mm/rev 3.33 scans/mm=1,000PPR
×
Diameter
: 5 7 dots (horizontal direction 5, vertical direction 7)
×
: 1 dot (1 scan)
: 1.8mm [horizontal direction 6 dots (6 scans)]
(inter-character dots 5 + inter-character space 1)
Pulley
: 5 7 dots (horizontal direction 5, vertical direction
×
: 1 dot (1 scan)
: 1.8mm [horizontal direction 6 dots (6 scans)]
(Inter-character dots 5 + inter-character space 1)