Rockwell Automation Allen-Bradley 842D, Руководство пользователя

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DeviceNet Objects B-7
Class Code 2F
hex
— Encoder
The Encoder Object contains all encoder data. All input data,
parameter data and status data are included here.
Class Attributes
Instance Attributes
Attr.
ID
Attribute Access Data Type Description
1 Revision Get USINT Revision = 01
2 Max. Instance Get USINT 1
Attr. ID Attribute Access Data type Description
1
Number of
attributes
Get USINT Number of supported attributes
2 Attributes Get
ARRAY
of USINT
List of supported attributes
3
Code
Sequence
Get/Set BOOL
Direction control for counting. Defines the increasing 'POSITION
VALUE' as clockwise shaft rotation or counter clockwise as seen
facing the shaft (CW, CCW).
5
Scaling
function control
Get/Set BOOL
Scaling Enable --Enabling scaling changes the 'POSITION
VALUE' I/O data resolution to 'MEASURING UNITS PER
REVOLUTION' and 'TOTAL MEASURING RANGE'
7
measuring
units per
revolution
Get/Set UDINT
Number of distinguishable steps per revolution. Less than
physical resolution.
8
Total
measuring
range in
measuring
units
Get/Set UDINT
The steps over total measuring range. The number is
automatically adjusted to a 2^0 - 2^13 multiple of 'RESOLUTION
PER REVOLUTION'.Example: if 'RESOLUTION PER
REVOLUTION' is set to 3600 then the possible 'TOTAL
MEASURING RANGE' values will be 3600, 7200, 14400, 28800,
... 29491200.
10 Preset value Get/Set UDINT This value will be applied to the 'POSITION VALUE'.
11 COS/delta Get/Set UDINT
A COS I/O message will be generated when the 'POSITION
VALUE' changes by this value. This value will be set to 5 if set to a
value larger than the 'TOTAL MEASURING RANGE'. Setting this
value to 0 disables COS messaging for 'POSITION VALUE'
changes. To lessen network traffic for high speed (4000 RPM+)
and/or high resolution (1024+ ppr) applications either: increase
the hysteresis to over 10% of the 'RESOLUTION PER
REVOLUTION' value, increase the 'Inhibit Time' ('Scanlist', 'Edit I/
O Parameters...', 'Advanced...') to 10 msec.
12 Position value Get UDINT
The current position value. This value is affected by 'PRESET
VALUE', 'RESOLUTION PER REVOLUTION', and 'SCALING
CONTROL'.
20 Velocity format Get/Set BYTE
This sets the format for velocity and acceleration values. The max
and min limits for velocity and acceleration are affected as well.
– 0 = Steps per second
– 1 = RPM
– 2 = RPS