6. RKC COMMUNICATION
IMS01J02-E2
53
Polling procedures
(1) Data link initialization
Host computer sends EOT to the controllers to initiate data link before polling sequence.
(2) Data sent from host computer - Polling sequence
Host computer sends polling sequence with the format shown below:
1.
Address (2 digits)
This data is a unit address of the SR Mini HG SYSTEM for polled and must be the same as the
unit address set value in item
5.2 Unit Address Setting (P. 48).
2.
Identifier (2 digits)
The identifier specifies the type of data that is requested from the SR Mini HG SYSTEM.
Always attach the ENQ code to the end of the identifier.
See
6.2 Communication Identifier List (P. 65)
.
3.
ENQ
The ENQ is the transmission control character that indicates the end of the polling sequence. The
host computer then must wait for a response from the SR Mini HG SYSTEM.
(3) Data sent from the SR Mini HG SYSTEM
If the polling sequence is received correctly, the SR Mini HG SYSTEM sends data in the following
format:
If the length of send data (from STX to BCC) exceeds 128 bytes, it is divided into blocks by
ETB. In this case, the succeeding divided data is sent after STX.
Address
3.
2.
1.
Identifier
ENQ
1
ENQ
M
0
2
Example:
Identifier Data
BCC
ETB
STX
3.
2.
6.
4.
1.
Identifier Data
BCC
ETX
STX
3.
2.
6.
5.
1.
or
