Rockwell Automation Ethernet Design Considerations Reference Manual - Manual (Page 82)

82 Rockwell Automation Publication ENET-RM002C-EN-P - May 2013
Chapter 5 Predict System Performance
Part Two: Predict Maximum input or Output Times for
CIP Connections
A CIP connection is an efficient communication path used for high
performance. The following are basic types of CIP connections:
• Rack-optimized
• Input or output data
• Produced tag
A CIP connection is bi-directional. During every RPI, each end of a connection
initiates a packet of information. A packet of information represents a
connection.
The type of data packet produced by each end of the connection depends on the
connection type as described below.
To predict the maximum input (I/O to controller) or output (controller to I/O)
times for CIP connections, complete the following steps.
1. Estimate the maximum time intervals for each CIP connection types
used in the control system.
2. If necessary, modify your system to get more throughput by performing
one or more of the adjustments described under
step 5 on page 81 .
3. If you have made modifications, verify that the modified system works by
recounting the connections and recalculating the packet rate capacity
loading.
Connection Type Scanner Adapter Producer
Controller Consumer
Controller
Rack-optimized Output data Input data N/A N/A
Input data Heartbeat Input data N/A N/A
Output data Output data Output data echo N/A N/A
Produced tag N/A N/A Tag data Heartbeat