Rockwell Automation D17846.2.4 CONTROLNET KT EMULA User Manual
Page 30

Publication 1784-6.2.4 - September 1997
3-10
How Your Driver Operates the KTCX Card
:0485h
Link Service
Access Point
PKTCX
00h= on-link packet
R . . . . . . . W
Off-link packets need 11 extra bytes which we start at byte
:0468h. The remaining bytes (:0486h-:07EFh) are shifted 11
places higher. LSAP specifies the type of packet and offset.
:0486h
CMD (PCCC)
PKTCX
---
R . . . . . . . . W
PCCC command code sent with bit 6 set to 01h. Refer to the
DF1 Protocol and Command Set (Pub. 1770-6.5.16).
:0487h
Message Status
PKTCX
---
R . . . . .. . . W
Indicates status of message transmission. Command mes-
sages always contain 00h. Reply messages may contain one
of the status codes listed in the DF1 Protocol and Command
Set (Pub. 1770-6.5.16).
:0488h
TNS (low byte)
PKTCX
---
R . . . . . . . W
The transaction numbers are 16-bit, 2-byte sequential track-
ing numbers. They make sure that commands and their
associated replies remain associated. If the host issues a
command, then it must generate and track the TNS.
:0489h
TNS (high byte)
PKTCX
---
R . . . . . . . W
Otherwise, the issuing PLC generates the TNS.
:048Ah
:07EFh
DATA
PKTCX
---
R . . . . . . . W
Bytes :048Ah-:07EFh contain the data to be transmitted (and
the response to packet, if any).
➀ CMD = Command From Host to KTCX; DIAG = Diagnostic Counter; STAT=Status; INI = Initialization; N/A = Not Applicable
➁ R = Read; W = Write