NEC NDA-30115-001 User Manual
Page 12
NDA-30115 Revision 1.0
Architecture
Property Management System - Communication Interface
The control codes used for the message texts are:
Table 2-6 Control Codes
Control Code
Hexadecimal
Value
Function
SYN
32
Synchronization code.
STX
02
Indicates the start of a block.
ETX
03
Indicates the end of a block.
ENQ
2D
Used as the start sequence code. It indicates a reception
request to the other side and a request to answer an infor-
mation block just sent.
request to the other side and a request to answer an infor-
mation block just sent.
EOT
04
Indicates the end of transmission of a block or release of
the data link by the sender.
the data link by the sender.
ACK0
10, 70
Used alternately, these indicate the positive acknowledg-
ment of an information block or a start sequence.
ment of an information block or a start sequence.
ACK1
10, 61
NAK
3D
Indicates the negative acknowledgment of an informa-
tion block or a start sequence.
tion block or a start sequence.
WACK
10, 6B
Used as the positive acknowledgment of an information
block or start sequence and indicates that the receiver
temporarily cannot receive data from the sender.
block or start sequence and indicates that the receiver
temporarily cannot receive data from the sender.
TTD
02, 2D
Indicates that the sender cannot transmit the next infor-
mation block after the receipt of the answer to the previ-
ous information block sent from the receiver.
mation block after the receipt of the answer to the previ-
ous information block sent from the receiver.
RVI
10, 7C
Indicates the positive acknowledgment of an information
block and asks the sender for sending rights.
block and asks the sender for sending rights.
PAD-L
55
Indicates the absolute beginning of the entire informa-
tion block.
tion block.
PAD-T
FF
Indicates the absolute ending of the entire information
block.
block.