
Chapter 4
CIP Over the Controller Serial Port
76
Rockwell Automation Publication 1756-PM020F-EN-P - January 2019
Name
Type
Description of Request Parameter
Semantics of Values
FNC
USINT
Fragmentation protocol function
See
Extra
USINT
Additional information for fragmentation protocol
Request Service
USINT
CIP Service Code
Request Path Size
USINT
Number of 16-bit words in the Request Path
Request Path
EPATH
Logical or Symbolic Segments, or both
Service Request Data
Service data as defined by the service. Size and type varies
Similarly, the CIP service response is returned in a PCCC command reply, as
shown in the following table.
Name
Type
Description of Request Parameter
Semantics of Values
CMD
USINT
Response = 0x0B + 0x40
See the
DF1 Protocol and Command Set Reference
publication
STS
USINT
Status (0 == Success)
TNSW
UINT
Used to match response with request
FNC
USINT
Fragmentation protocol function
See Fragmentation Protocol
Extra
USINT
Additional information for fragmentation protocol
Reply Service
USINT
CIP Service Code + 0x80
See CIP Services.
Reserved
USINT
00
General Status
USINT
ss
Extended Status Size
USINT
nn
Extended Status
Only present if Size > 0
Service Response Data
Service determines whether present or not, and the size/ data
type
See also
Connected Explicit Messages through PCCC
PCCC Command Code 0A provides CIP explicit-message connection
behavior. The services are used within these commands. For example, the
only difference between connected explicit messages through PCCC and an
EtherNet/IP explicit message connection is the wrapper that the CIP service
is carried in. EtherNet/IP network uses Ethernet and TCP/IP technology and
this uses DF1 and PCCC.
Tip:
Rockwell Automation assumes that you are familiar with CIP and the information related to CIP that is discussed here. The details of the
CIP portions of the frame are not fully described here. References to where more detailed information can be found are provided later. If
you are not familiar with CIP, a tutorial is available for purchase at
http://www.rockwellautomation.com/enabled/cipetraining.html
The table shows the fields used and where more information can be found
about specific fields of the command structure.
Connected Explicit
Messages through PCCC