Each field controller has an EOL switch, which, when set to ON (up), sets the field controller as a terminating device on the bus. See Figure 1 jea1558360005689.html#jea1558360005689__fig_y4y_tcv_lhb for the EOL switch location on the field controller. The default EOL switch position is OFF (down). The amber EOL LED illuminates to show the EOL is active.
Figure 1. EOL switch positions
To set the EOL switch on a field
controller:
- Determine the physical location of the controller on the SA or FC Bus.
- Determine if the controller must be set
as a terminating device on the bus. Note: The EOL termination rules for SA Buses and FC Buses are different. Refer to the MSTP Communications Bus Technical Bulletin (LIT-12011034) for detailed information regarding EOL termination rules and EOL switch settings on SA and FC Buses.
- If the controller is a terminating
device on the FC Bus, set the EOL switch to ON. If the controller is not a
terminating device on the bus, set the EOL switch to OFF. Note: When the EOL switch is set to ON, the LED light on the face of the controller is illuminated.