Delta RMC101 - Manual (Page 358)

RMC100 and RMCWin User Manual
5-108
Configuration Connection
Point Must be 4 (Configuration)
Configuration Data (Data Segment) May be omitted or contain any number of bytes.
All bytes except the first one must be zero. The
first byte specifies the Broken Connection Action,
as described in Handling Broken I/O Connections.
5.2.6.3.7 EtherNet/IP Performance
5.2.6.3.7.1 EtherNet/IP Performance Overview
The following factors affect the determinism and performance of an EtherNet/IP I/O connection:
• Load on the RMC ENET
The RMC ENET load is described in Evaluating the Load on the RMC ENET.
• Load and bandwidth of the 1756-ENET or 1756-ENBT module
The 1756-ENET load is described in Evaluating the Load on the 1756-ENET, and the 1756-ENBT
load is described in Evaluating the Load on the 1756-ENBT.
• LAN Component Capabilities (10/100 Mbps, Half/Full-Duplex, Hubs/Switches)
The effects of these capabilities are described in Predicting the Effect of Collisions.
• Utilization of the LAN Bandwidth
Utilization is defined and its effects are evaluated in Predicting the Effect of Collisions.
In addition to these specific considerations, the Setting Up Large EtherNet/IP Networks topic
gives suggestions for reducing collisions and the load on network components in large
EtherNet/IP networks.
5.2.6.3.7.2 Evaluating the Load on the RMC ENET
The RMC ENET's bandwidth is limited to 500 frames/second. This bandwidth is shared among
the one to four I/O simultaneous connections supported by the RMC. See Establishing Multiple
I/O Connections with a Single RMC for details on having multiple connections. The important
point from this topic is that all connections for each RMC must have the same RPI.
To compute the bandwidth requirement on the RMC ENET use the following formula:
Frames/Second = (1 + connections) / RPI
This value should be kept below 90% of the RMC ENET bandwidth, or 450 frames/second. Using
too close to the maximum bandwidth would result in decreased determinism and degraded
performance of messaging tasks such as using ControlLogix MSG blocks and connecting via
RMCWin.
The following table gives the minimum RPI allowed to keep the bandwidth under 90% for one to
four connections:
I/O Min