3. RKC COMMUNICATION PROTOCOL
IMR02F04-E1
19
3.1.1 Polling procedures
(1) Data link initialization
Host computer sends EOT to the PG500s to initiate data link before polling sequence.
(2) Data sent from host computer - Polling sequence
The host computer sends the polling sequence in the following formats:
1.
Address (2 digits)
The device address specifies the PG500 to be polled and each PG500 must have its own unique
device address.
This data is a device address of the PG500 to be selected and must be the same as the device
address set value in item
2.3 Setting (P. 10)
.
The polling address which transmitted a message once becomes effective so long as data
link is not initialized by transmit and receive of EOT.
2.
Identifier (2 digits)
The identifier specifies the type of data that is requested from the PG500. Always attach the ENQ
code to the end of the identifier.
For details, refer to
5. COMMUNICATION DATA LIST (P. 42)
.
3.
ENQ
The ENQ is the transmission control character that indicates the end of the polling sequence.
The ENQ must be attached to the end of the identifier.
The host computer then must wait for a response from the PG500.
(3) Data sent from the PG500
If the polling sequence is received correctly, the PG500 sends data in the following format:
1.
STX
STX is the transmission control character which indicates the start of the text transmission
(identifier and data).
Identifier
Address
Example:
ENQ
1
M
0
2
Identifier Data
BCC
ETX
STX
3.
2.
3.
4.
1.
3.
2.
1.
ENQ
