Supplement operating manual for DREHMO i-Matic actuators with integrated
MODBUS fieldbus interface
Wenden, 21.03.12
Page 14 of 18
Prepared by: Ste
2.5.1.2
Bus termination
The termination of the bus line can be done individually for the channels 1, 2 by setting the
slide switches S3, S4 on the connection board DiM-19 in the compact plug. If the
termination on one of the channels is activated, the outgoing line of this channel is
disconnected from the master.
example for termination with slide switch S3, S4 on DiM-19 connection board
- channel 1 without termination – bus connection forward to next device
- channel 2 termination activated – last device on bus segment
2.5.1.3
Grounding of the cables´ shields in case of copper cable use
To avoid high currents on the cables´ shields in systems with very different earth potentials,
the shields of the cables connected to the inputs and those connected to the outputs can be
grounded directly, or using a combination of resistor and capacitor using the grounding
switches ( see 2.5.1.1) on the connection board. The resistor reduces DC-currents,
whereas the capacitor has a low impedance for fast changes between ground potentials.
High impedance grounding of shield
