User's Manual

11
(6） Transmission frame error (Master receive)
① Session starts when ENQ is sent from master to slave.
② Slave acknowledges by returning ACK to master.
③ Master sends read command.
④ Slave returns ACK code to acknowledge read command.
⑤ Slave sends read data to master.
⑥ For some reason, master fails to receive read data.
⑦ Slave fails to receive acknowledgment of read data and attempts to resend every 3 seconds for 3
times.
⑧ After the third failure, slave aborts the sequence and ends communication.
HITACHI
Master (PC)
1
2
6
ENQ code (05H)
ACK code
(
06H
)
Read data (ASCII code)
Read data (ASCII code)
Read data (ASCII code)
7
Read data (ASCII code)
8
3
4
Read command (ASCII code)
ACK code
(
06H
)
5
3 second
elapse
3 second
elapse
3 second
elapse
Slave
(KP-F500PCL/SCL
KP-FR500PCL/SCL)