Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 447)

Section 8
Communication Interface
8-14
Data Transmitting Sequence
Figure 8.13 shows the data transmission sequence of the control.
Figure 8.13
Data Transmission Sequence
Data transmission from the control
Control codes from a peripheral device (tape reader, etc)
DC2 Leader Program data Program data MO2EOT DC4
DC3 DC1 DC3 DC1
1 2 3 4 5 6 7 8
11357-I
DC2 DC2
1. The control transmits the DC2 code in three--second intervals until it
receives the DC1 code from the peripheral.
2. Upon reception of the DC1 code, the control begins data
transmission.
3. The peripheral transmits the DC3 code when its buffer cannot accept
the received data.
4. Upon reception of the DC3 code, the control stops data transmission
within two characters.
5. The peripheral transmits the DC1 code when it is ready to receive
data again.
6. The control, upon reception of the DC1 code, begins data
transmission again.
7. The control transmits the DC4 code after it transmits the M02 or M30
code.
8. The peripheral transmits the DC3 code when it receives the DC4 code
to end data input.