Setting the terminating resistor in the CAN bus network (termination)

In a CAN bus network such as at ABUControl, a central CAN bus line runs as the backbone. On both ends of the backbone of the CAN bus line the terminating resistors must be set. This means that disruptions in the CAN bus line can be prevented. Further CAN bus devices of the CAN bus network can be connected on this backbone in a radial manner without terminating resistor to a CAN distributor.

Depending on the crane, the CAN bus network can vary greatly. For example, the position of the LED matrix display must be taken into account, as well as the number of trolleys and the type (twin hoist with two hoist drives per trolley), among other considerations.

This section describes both of the two basic CAN bus networks for cranes with one and with two trolleys. For all other CAN bus networks, contact ABUS Service.

If faulty CAN bus devices are exchanged (e.g. PLC, CAN distributor, LED matrix displays, etc.), the terminating resistor on the new CAN bus device must be switched the same as it was on the faulty CAN bus device.

Only for cranes with one trolley

CAN distributor in the crane panel with switched-off terminating resistor	CAN distributor in the trolley with terminating resistor

LED matrix display on the backbone with terminating resistor	Terminating resistor

In the CAN bus network of ABUControl for a crane with one trolley, the backbone runs from the hoist panel (+KA) through the crane panel (+KR) to the LED matrix display.

The terminating resistors are switched on in the CAN distributor in the hoist panel (+KA) and in the LED matrix display. The terminating resistor in the CAN distributor in the crane panel (+KR) is switched off.

Only for cranes with two trolleys

CAN distributor terminating resistor "off"	CAN distributor in Trolley 1

CAN distributor in Trolley 2	Terminating resistor "on"

In the CAN bus network of ABUControl for a crane with two trolleys, the backbone runs from hoist panel 1 (+KA1) through the crane panel (+KR) to hoist panel 2 (+KA2).

The terminating resistors are switched on in the CAN distributors in the two hoist panels 1 + 2 (+KA 1 und +KA2). The terminating resistor in the CAN distributor in the crane panel (+KR) is switched off.

On the faulty LED matrix display, check whether the terminating resistor was switched on or switched off.

Only with 60 mm LED matrix display

On the circuit board are two jumpers for the terminating resistors. One is for the terminating resistor in the CAN bus network, the other for the terminating resistor in the Modbus network. To avoid errors, bother jumpers should always be inserted jointly and consistently.

	Terminating resistor jumper

Plug in both jumpers for the terminating resistor:

─ Plug the jumper on both contacts directly next to "ON" to switch on the terminating resistor.

─ Plug the jumper on both contacts that point away from "ON" to switch off the terminating resistor.

Only with 120/180 mm LED matrix display


	Terminating resistor jumper

Plug in both jumpers for the terminating resistor:

─ Plug in the jumper on both contacts directly under "OFF" to switch off the terminating resistor.

─ Plug in the jumper on both contacts in the centre and to the right of "OFF" to switch on the terminating resistor.

Only with absolute rotary encoder "AWG"

In most cases, the terminating resistor must be switched off on the absolute rotary encoder. In special cases, the terminating resistor may need to be switched on.

Sliding switch for terminating resistor

Check whether the terminating resistor on the faulty absolute rotary encoder was switched on (both sliding switches toward outside to ON) or switched off (both sliding switches toward inside).

If a "GPK" hoist limit switch was previously installed with a "Kübler" absolute rotary encoder: The terminating resistor was switched off.

Switch the terminating resistor on the new absolute rotary encoder as it was on the faulty absolute rotary encoder (switch on or switch off).

Only with "Kübler" absolute rotary encoder

In most cases, the absolute rotary encoder requires no terminating resistance. In special cases however, terminating resistance may need to be present.

Since no terminating resistor can be switched on directly on the "Kübler" absolute rotary encoder, a CAN distributor can be installed in the hoist limit switch housing. The terminating resistor can be switched on at the CAN distributor.