Rockwell Automation 1775-KA PLC-3 Communication Adapter Module User Manual - Manual (Page 223)

Detailed Flowcharts
Appendix D
DĆ13
Figure D.14
SEND Subroutine
SEND
Disable Processor
Interrupts
Enable UART
Transmit Interrupt
UART
Transmitter
Empty
?
Yes
Disable UART
Transmit Interrupt
No
SLEEP
Suspend at
TXWAIT
Output Byte
to UART
Enable Processor
Interrupts
Return
Indivisible Zone
NOTE: This figure assumes the use of
a Z80 SIO
Input:
•
Link Data Byte
Common:
•
TXWAIT: A Sleep Variable
10084–I