Rockwell Automation 1769-ADN Compact I/O 1769-ADN DeviceNet Adapter - Manual (Page 142)

Publication 1769-UM001B-EN-P - October 2002
6-30 Application Examples
PCCC Messaging
PCCC stands for “Programmable Controller Communications
Commands”. PCCC provides point to point and master/slave
communications between devices. PCCC is an open protocol that is
built into all Allen-Bradley controllers, and many other Allen-Bradley
and third-party products.
PCCC messaging has been used for many years on DH-485, DH+ and
Ethernet networks, and for point-to-point communications between
Allen-Bradley controllers. PCCC messaging allows program
upload/download to occur over DeviceNet, and allows users to
message across DeviceNet, just like they did using DH-485 or DH+.
There are a number of devices that support PCCC messaging over
DeviceNet, including the 1761-NET-DNI (DNI), 1203-GU6 interface,
and RSLinx. If the DeviceNet network has DNI’s, either device can
initiate a PCCC message.
CIP Messaging
See CIP Generic on page 6-35.
Program Upload/Download Before performing a program upload/download through the scanner,
be sure that the module is properly installed in the system, and that a
terminator is present at the end of the Compact I/O expansion bus.
IMPORTANT
DeviceNet networks can operate at 125K, 250K or
500K baud. Depending on network size and
communication activity, performing program upload
and/or download operations while the network is
controlling an application may impact control system
performance. It is up to the user to know and
understand how upload/download will impact their
operations.