Siemens 500 NIM - Manual (Page 35)

Network Design Considerations 2-17 SIMATIC TIWAY I Series 500 NIM User Manual
Local Line Biasing (continued)
Termination of the Local Line must be at the tap housings at the extreme
ends of the network spine, and is accomplished as follows:
1. The factory-installed termination resistors in the tap housing (see
Figure 2-6) are left in place in the tap housing which is to be used to
terminate the Local Line.
2. If the termination resistors are used and the attached NIM has a Bias
Switch, the bias switch should be moved downward to the ON position.
NETWORK CABLE
INPUT OUTPUT
G
W
B
G
W
B
B W G
CABLE TO MODULE
TERMINATION
RESISTORS
68 ohms
5%
1/4 WATT
Figure 2-6 Terminating the Local Line
NOTE: All Siemens tap housings contain factory-installed terminating
resistors. If the Tap Housing is not used to terminate the Local Line, the
terminating resistors must be removed when the output cable is attached.