Manual
| System Manual
36
Grounding
A short (as short as possible), low-impedance connection between the grounding point and the refer-
ence ground is essential to divert interference voltages running between the device and reference
ground.
The inductivity of standard FE conductors is a high impedance for high-frequency interference voltag-
es. For this reason, the use of grounding straps is advisable. If this is not possible, a fine-wire FE con-
ductor should be selected with the largest possible cross section, and the connection to ground should
be kept as short as possible.
Cable Routing
You can avoid EMC problems by observing elementary basic rules of cable routing:
Route data lines as far as possible away from power lines.
Route data lines and power lines at least 10 cm apart.
Intersect data and power lines at right angles only.
Route data and power lines in separate, shielded compartments.
Remember the interference potential of other devices or lines when routing the cables.
Place frequency converters, motor lines, and other devices and lines that emit high-frequency
intereference at the greatest possible distance.
Voltage Drops
Short-term voltage drops (<3 ms) normally pose no operational problems as the electronics are pro-
tected by capacitors integrated in the power circuits. This does not apply to the power supply of the
sensors and actuators connected to the module. Their high power requirement cannot be covered by
the capacitors integrated in the device. For this reason, even transient interruptions of the actuator
supply can result in undesirable switching operations.
Due to the integrated input filter, a change in the input signal of less than 1 ms does not cause a
change of the input state signaled to the Master. Longer interruptions of the sensor supply may cause
changes of the input signal.
