161
[Reference]
Reference
Host MINAS-E
Received
Data
Transmitted
Data
(1) ENQ (05h)
(2) EOT (04h)
(3) Data Block
(4) ACK (06h)
(or NAK (15h))
(5) ENQ (05h)
(6) EOT (04h)
(7) Data Block
(8) ACK (06h)
(or NAK (15h))
x
1
x
3
x
4
x
5
x
6
S TATU S
ALM CODE
Line Control
Direction of transmission and conflict are solved.
Reception mode …The module enters reception mode after receiving ENQ and returning EOT.
Transmission mode … The module enters transmission mode after sending ENQ and receiving EOT.
When there occurs a conflict between the transmitting module and receiving module:
When subsequent to transmission of ENQ, a slave receives ENQ while waiting for EOT, priority is given to
ENQ sent from a maser, and the slave enters the reception mode.
Transmission Control
Entering transmission mode, a module transmits a command block continuously and then waits for reception
of ACK. When the module receives ACK, transmission is complete. When the number of transferred
command bytes is incorrect, ACK may not be returned. When ACK is not returned within T2 period, or when
NAK or any code other than ACK is received, transmission retry will be executed. The retry will start with
ENQ.
Receiving Control
Entering receiving mode, the module receives transmitted blocks continuously. It obtains the number of
command bytes from the first byte, and receives as many command bytes as that number plus 3. When the
sum of received data is zero, reception is considered successfully ended and ACK is returned. When
abnormal checksum or timeout between characters occurs, NAK is sent.
Transmission Sequence
Transmission Protocol
RS232C