PM550 CIM Requirements
A-3
TIWAY 1 TI505 NIM User Manual
2.
If more than one CIM is attached to a Local Line, place CIMs at the extreme ends
of the Local Line trunk. Install the jumpers provided with the outermost CIMs
in accordance with the instructions in the PM550 CIM User’s Manual, Manual
Number PM550–1101154–4. This will apply the correct bias to the Local Line to
prevent oscillations of the CIM receivers.
To terminate the Local Line, replace the existing terminating resistors inside the
outermost CIM tap housings with 150-ohm resistors between the LLM+ and the
cable shield, and also between LLM– and the cable shield. This resistance value
is 150 ohms in each instance, and the connection is in accordance with
instructions inside the tap housing. The combination of termination resistors in
the CIM together with these 150-ohm resistors, provides the correct Local Line
termination.
The following block diagram Figure A-1 illustrates the proper placement of the CIMs and
the termination resistors for networks having CIMs and NIMs without the bias switch.
TIWAY I
PRIMARY
TERMINATING RESISTOR(150 ohms)
INSTALLED
NOT INSTALLED
T–TAP
T–TAP
NOT INSTALLED
INSTALLED
T–TAP
T–TAP
TERMINATING RESISTOR(150 ohms)
T–TAP
CIM
PM550
JUMPERS
INSTALLED
SELECTED
CIM
NOT SELECTED
BIAS
CIM
JUMPERS
INSTALLED
NOT SELECTED
CIM
PM550
SELECTED
BIAS
NIM’s: BIAS OFF
CIM’s: JUMPERS OFF
Figure A-1 Local Line Bias and Termination
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com