2.2 Structure of Command Text
H8GN
2-5
2.2 Structure of Command Text
An MRC (Main Request Code) and SRC (SubĆRequest Code) followed by
the various required data is transferred to the command text.
MRC
SRC
Service request PDU
Data
MRES (Main Response Code) and SRES (SubĆResponse Code) are
transferred followingthe above MRC/SRC. Data is then transferred
followingthese MRES and SRES.
MRC
SRC
MRES
SRES
Service response PDU (during normaloperation)
Data
If the specified command text could not be executed, only the MRC/
SRC and MRES/SRES become the target response PDUs.
MRC
SRC
MRES
SRES
Service response PDU (at nonĆexecution of specified command text)
MRES/SRES becomes the response code except when processing
ends in normal completion."
Areas comprise only variable area.
The followingdefines variable area type codes.
Variable
type
Description
C0
R/O (read only) parameter.
C1
Protect level parameter.
C2
Operation and adjustment level parameter.
C3
Initialsetting, communications setting and advanced function setĆ
ting level parameter.
Each of the variable types is appended with an address. Express addresses
in 2Ćbyte hexadecimal code.
The number of elements is expressed in 2Ćbyte hexadecimal code. Specify
the number of elements within the range 0 to 2".
For example, when the number of elements is 0002", specify data for two
items from the address.
JPDU structure
JArea definitions
JType code
(variable type)
JAddresses
JNumber of
elements
