The SA Bus Performance attribute, which is located on the Device Information Screen, indicates the current performance of the bus, such as low, medium, or high. Values of COV Receive Rates and Average Token Loop times are indicators of SA bus performance. See the following table.
| SA Bus Performance | Description |
|---|---|
| LOW | Average COV Receive Rate greater than 600, OR Average Token Loop greater than 2,000 ms. |
| MEDIUM | Average COV Receive Rate greater than 300 and less than or equal to 600, OR Average Token Loop greater than 1,000 ms and less than or equal to 2,000 ms. |
| HIGH | Average COV Receive Rate less than or equal to 300, AND Average Token Loop less than or equal to 1,000 ms. |
| NOT APPLICABLE | Indicates unsupported data type, such as Ethernet. |
Maximum traffic over control networks is mostly due to noisy analog signals. In the event you are experiencing low or medium bus performance, try increasing the update interval time of the AI points on your Point Expansion Modules. AI points on SA Bus devices periodically send COV messages back to the controller regardless of a change in value. This guarantees closed loop application control, but also increases periodic traffic on the bus.