Communication Protocols
Copyright IXXAT Automation GmbH
95
IEM Manual, 1.5
the relation between EMI API services and EIP services depending on the ac-
cess rights and location of the variable.
Location
Access rights
Services
Host
SHM
cyclic
SHM
acyclic
re-
mote
write read
read
write
EMI service
(local request)
EIP service
(remote request)
1
x
x
direct access
Set_Attr_Single
2
x
x
direct access
Get_Attr_Single
3
x
x
direct access
Set_Attr_Single
Get_Attr_Single
4
x
x
EMI_ioCyclDataRead
Set_Attr_Single
5
x
x
EMI_ioCyclDataWrite
Get_Attr_Single
6
x
No!
7
x
x
EMI_ioCyclDataRead
Set_Attr_Single
8
x
x
EMI_ioCyclDataWrite
Get_Attr_Single
9
x
x
EMI_ioCyclDataRead
EMI_ioCyclDataWrite
Set_Attr_Single
Get_Attr_Single
10
x
GET_VALUE
SET_VALUE
x = choosen; No! = not possible
Figure 5-6: Relation between EMI and EIP services
Example (see row seven of table): a variable may be located in the SHM sec-
tion of acyclic data. This variable shall be writable by the network. Thus the
access right is “write” (
COM_k_ATTR_WRITE
). To change this variable value the
remote device sends a “Set_Attribute_Single” request via EtherNet/IP to the
IEM. The host may read the new value by means of the EMI service request
“GET_VALUE”.
5.2.2.1 Object model
The following describes the common objects used by the “Communications
Adapter Device” profile of the IEM. Additional information e.g. the description
of the attributes and the semantic of their values can be found in [EIP1] and
[EIP2].
Identity object (0x01)
Class attributes
ID
Name
Access
1
Revision
get
2
Max. instance
get
3
Number of instances
get
4
Optional attribute list
get