Hitachi HV-F130SCL Operation Manual page 28

(3） Processing at the time of SUM value error occurred
HITACH
3CCD
Slave
(HV-F32SCL)
① Transmitted to the slave the command of illegal SUM value from the master.
② If the SUM value is illegal received command, the slave discards the contents of the received,
send "NAK" to the master, the end of the handshake.
(4） Processing when a communication error has occurred.
HITACH
3CCD
Slave
(HV-F32SCL)
① Master sends data, but error detected (framing, over-run error).
② Master If the ACK response does not come within three seconds, to re-send the command.
③ Master send the correctly data.
④ Slave sends a "ACK code" after receiving the correctly data.
Illegal command SUM value
(STX-ETX.??)
NACK code (15H)
2
1
(error occurs)
（STX-ETX.SUM）
(error occurs)
（STX-ETX.SUM）
(correctly data)
（STX-ETX.SUM）
normal)
ACK code (06H)
4
1
Master (Machine)
1
3 second
elapse
2
3 second
elapse
3
Master (Machine)
16