D8 Series User’s Guide
Chapter 3: Communicating by DeviceNet
58
Ratio Object
The Ratio Object provides read/write access to all ratio parameters. Instance 0 of this object
contains the class attributes listed in Table 3.32. The four-loop controller has four additional
instances, and the eight-loop controller has eight additional instances, each containing the attributes
listed in Table 3.33. Instance 1 corresponds to loop 1, instance 2 corresponds to loop 2, and so on.
Table 3.31
– Ratio Class and Services
Class Code
69 hex
Class Services
0E hex Get Attribute Single
Instance Services
0E hex Get Attribute Single
10 hex Set Attribute Single
Table 3.32
– Ratio Class Attributes (Instance 0)
ATTRIBUTE
ACCESS
NAME
TYPE
DESCRIPTION
1 (1 hex)
Get
Revision
UINT
Revision of this object
2 (2 hex)
Get
Max instance
UINT
Maximum instances of this object (8)
3 (3 hex)
Get
Number of instances
UINT
Number of object instances
Table 3.33
– Ratio Instance Attributes (Instances 1 to 4 or 8)
ATTRIBUTE
ACCESS
NAME
TYPE
DESCRIPTION
100 (64 hex)
Get/Set
Ratio Master Loop
USINT
101 (65 hex)
Get/Set
Ratio Low Set Point
INT
102 (66 hex)
Get/Set
Ratio High Set Point
INT
103 (67 hex)
Get/Set
Control Ratio
UINT
104 (68 hex)
Get/Set
Ratio Set Point Differential
INT
NOTE!
All successful explicit message responses from a Set service will contain no
data. The response will be a two-byte message containing the requester’s node address
and service code (with R/R bit set).
Cascade Object
The Cascade Object provides read/write access to all cascade parameters. Instance 0 of this
object contains the class attributes listed in Table 3.35. The four-loop controller has four additional
instances, and the eight-loop controller has eight additional instances, each containing the attributes
listed in Table 3.36. Instance 1 corresponds to loop 1, instance 2 corresponds to loop 2, and so on.
Table 3.34
– Cascade Class and Services
Class Code
6A hex
Class Services
0E hex Get Attribute Single
Instance Services
0E hex Get Attribute Single
10 hex Set Attribute Single