7.2 Service Communication Function
The D.Station use explicit communications to receive service requests from another node.
When a requested service is addressed to an object within the D.Station, the it executes the
service and transmits a response.
Other nodes (master) are able to receive the results by requesting required services using this
explicit communication.
The D.Station supports the following services:
● Transmits the D.Station's communication information such as transmission/reception ID
and data length to a specific node.
● Transmits the D.Station's maintenance information such as manufacturer name, device
type, status information to a specific node.
7.2.1
Communication specifications
Table 7-2 shows the service (explicit) communication specifications.
Table 7-2 Service (Explicit) Communication Specifications
No.
1
Requested maximum data length
Responded maximum data length
2
Message group used
3
Message ID
4
Data synchronicity assurance
5
Multiple-instance startup prevention unit
The number of service requests that can be simultaneously issued from a client (master) to
the D.Station is one per a node. If next request is made while the previous request is being
processed, the latter request will be rejected.
7.2.2
List of supported services
The D.Station supports the services shown in Table 7-3.
Service code
0x0E
Get_Attribute_Single
0x10
Set_Attribute_Single
Item
Table 7-3 List of Supported Services
Service name
Request transmission of one
attribute data
Request for a setup of one
attribute data
7 COMMUNICATION FUNCTION
Specifications
Server
70 bytes
70 bytes
3 or 2
Fixed at 4
70 bytes
In the unit of a node
Service description
− 61 −
Remarks
Fixed
Same size as No. 1
Fixed
Use
For reading one attribute data
about an object
For setting one attribute data
about an object