
IG-267-EN versión 01; 07/04/2017
109
General Instructions
ekor
.rpa
Communications
And in slave to master direction:
#
Name
Description
0
CONFIRM ACK
Positive confirmation
1
CONFIRM NACK
Negative confirmation
8
RESPOND DATA
Response with application data
9
RESPOND NO DATA
Response without application data
11
RESPOND LSTS
Response to link status request
14*
RESPOND LERROR
Response indicating the slave link level does not work properly
15*
RESPOND NO IMP
Response indicating the functionality associated to the requested data has not been implemented in the slave
Table 12.17.
Frames in slave to master direction
Application level
For exchanging data between the application functions,
between the master and slave equipment, data are
encapsulated in the variable-length frames. The application
data are named ASDU (Application Service Data Unit) and
have a common header that indicates their type followed
by specific data for each one.
The structure of the header, or data unit identification, is as
follows:
Offset
Name
Description
0
Typ
Data type identifier
The numeric value stored in this field is used to name the application data in an unequivocal way
1
Vsq
Variable structure qualifier
Indicates the number of data structures included in ASDU
2
Cot
Cause of transmission. Indicates the cause of the data transmission
3
Addr
ASDU address
ASDU application level address. It does not have to be the same as the link level address, since a link
connection could be used for several application connections. However, in PROCOME it is the same
Table 12.18.
Data unit identification structure
The table below shows the information object associated
to the data type. The structure of this object depends on
the data transmitted in each case, but each of them have
the same start, the information object identifier whose
structure is as follows:
Offset
Name
Description
4
Fun
Function type
5
Inf
Information number
Table 12.19.
Information object identifier structure
Finally, the information object data from offset 6 is included
in the application data field.
The ASDUs used in PROCOME have preset values for each of
the header fields.
Содержание ekor.rpa Series
Страница 115: ......