6.14 Setting Unit Systems
6.14.3 Setting the Acceleration Reference Unit
6-48
6.14.3
Setting the Acceleration Reference Unit
Set the acceleration reference unit [Acc Unit] in
acceleration user unit
(2703h).
Setting range: 1/128
≤
Numerator/Denominator
≤
262,144
(Alarm A.A20 will be detected if the setting exceeds the setting range.)
6.14.4
Setting the Torque Reference Unit
Set the torque reference unit [Torque Unit] in
torque user unit
(2704h).
Setting range: 1/256
≤
Numerator/Denominator
≤
1
(Alarm A.A20 will be detected if the setting exceeds the setting range.)
For a Rotary Servomotor with an encoder resolution of 24 bits (16,777,216), Pn20E (Electronic
Gear Ratio (Numerator)) is automatically set to 16 and Pn210 (Electronic Gear Ratio (Denomina-
tor)) is automatically set to 1. Therefore, the encoder resolution will be equivalent to 20 bits
(1,048,576). Consider this when you set the position reference unit in
position user unit
(2701h).
Index
Subin-
dex
Name
Data
Type
Access
PDO
Mappings
Value
Saving to
EEPROM
2703h
0
Number of entries
USINT
RO
No
2
No
1
Numerator
UDINT
RW
No
1 to 1,073,741,823
(default: 1)
Yes
2
Denominator
UDINT
RW
No
1 to 1,073,741,823
(default: 1)
Yes
Acceleration Reference Unit Setting Example (Electronic Gear Ratio Setting Example for a
Ball Screw)
•
Acceleration User Unit (2703h)
Converting one user-defined acceleration reference unit [0.1 mm/s
2
] into [10
4
inc/s
2
]:
Therefore, the objects are set as follows:
Object 2703h: 01 (Numerator) = 1,048,576
Object 2703h: 02 (Denominator) = 600,000
Important
Example
1,048,576
6
×
10
5
1 [Acc unit]
=
=
16,777,216 [inc]
×
(1/16)
6 [mm]
×
0.1 [mm/s
2
]
×
10
-4
[10
4
inc/s
2
]
Index
Subin-
dex
Name
Data
Type
Access
PDO
Mappings
Value
Saving to
EEPROM
2704h
0
Number of entries
USINT
RO
No
2
No
1
Numerator
UDINT
RW
No
1 to 1,073,741,823
(default: 1)
Yes
2
Denominator
UDINT
RW
No
1 to 1,073,741,823
(default: 10)
Yes
