KLS Martin group marLED E3 - Page 35

Service Manual
Operating Lights marLED® E3, E9, E9i, E15, battery and
marLED® E3 on ceiling tube Ø 110 mm
Revision 2 35
Rules for setting the terminating resist
or
•
The terminating resistor should be set to ON for the two CAN bus users farthest apart from each other.
•
Only one terminating resistor may be switched on for each light. For marLED® E lights with surgiCam,
the marLED® terminating resistor must be switched off and only the terminating resistor of the
surgiCam daughterboard is switched on according to table, see section 6.4.4 “DIP switch SW1
surgiCam”, page 51.
•
The terminating resistor of a surgiCam COM interface must always be set to ON.
•
The terminating resistor of a marLED® COM interface may only be set to ON if no surgiCam COM
interface is included in the configuration.
•
The terminating resistor of the standard CAN board is normally set to OFF. In exceptional cases, e.g. if
long cables are used, point-to-point termination can be required (resistor switched on).
•
The terminating resistor of the coupler is factory-preset to ON. To assure proper functioning of the
coupler, never switch off this terminating resistor! Also see section 6.1.14 “Troubleshooting on Bus
Coupler”, page 39.
CAN bus malfunction
Once all devices are connected, the resistance between CAN
L and CAN H must range between 40 and
120
Ω to ensure perfect CAN bus functioning.
Long cables can additionally increase the measured resist
ance value.
•
Prior to each resistance measurement, make sure that the system is fully wired and off-circuit. If not,
the measured resistance value is useless.