Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 207)

Detailed Flowcharts
Appendix D
DĆ3
Figure D.2
Transmitter Routine for FullĆDuplex Protocol
XMIT
GETMSG
Get Message
from Network
Layer
Reset NAK
and Timeout
Counters
SENDM
Send Message
WTAK
Wait for ACK,
NAK, or Timeout
SENDCTL
Send
DLE ENQ
Received
DLE NAK
?
Received
DLE ACK
?
3*
NAKs
Received for This
Message
?
3*
Timeouts
for This
Message
?
SIGFAIL SIGOK SIGFAIL
Tell Network
Layer of
Failure Tell Network
Layer Message
Was Sent Tell Network
Layer of
Failure
11653
Yes
No
No
Yes
No
Yes
Yes
No
Internal Storage
•
NAK Counter
•
Timeout Counter