SHEET
6
10
DF022-4PE-S1
2
1
3
4
F
E
D
C
B
A
F
E
D
C
B
A
2
1
3
4
DWG.
No.
d)
Data transmitted by master (data error process)
1) Session starts when ENQ is sent from master to slave.
2) Slave acknowledges by returning ACK to master.
3) Master sends data, but error detected (framing, over-run error).
4) Slave detects error and does not accept data.
5) Sequence 3 and 4 repeats, then master transfers normal data.
6) Slave detects normal data and returns ACK code to master to end the session.
Master
Slave
ENQ code (05H)
1)
ACK code (06H)
2)
3)
Send data (error occurs)
ACK code (06H)
Send data (error occurs)
Send data (data normal)
4)
3 seconds elapse
3 seconds elapse
5)
6)
RS
RS
RS
RS----232C
232C
232C
232C
conv
conv
conv
conversion circuit
ersion circuit
ersion circuit
ersion circuit