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AFDZP0BA – VCM Zapi 2uC - User Manual
case there is no power bridge commutating large current at high frequency
thus the problems related to emission should be less relevant than in other
Zapi product. The main source of emission may be the CANbus because its
wire is often very long and it can be a quite good antenna. As usual, a good
layout of the cables and their shielding can solve the majority of the emission
problems.
3)
The
electromagnetic immunity
concerns the susceptibility of the controller
with regard to external electromagnetic fields and their influence on the
function of the electronic device.
There are well defined tests which the machine has to be exposed to.
These tests are carried out at determined levels of electromagnetic fields, to
simulate external undesired disturbances and verify the electronic devices
response. Normally the same prescriptions (cable layout, shielding..) used to
solve emission problems can be applied to solve immunity problems too.
4)
The
ESD
, concerns the prevention of the effects of electric current due to
excessive electric charge stored in an object. In fact, when a charge is
created on a material and it remains there, it becomes an “electrostatic
charge”; ESD happens when there is a rapid transfer from a charged object
to another. This rapid transfer has, in turn, two important effects:
A) this rapid charge transfer can determine, by induction, disturbs on the
signal wiring and thus create malfunctions;
this effect is particularly
critical in modern machines, where CANbus lines are spread
everywhere on the truck and which carry critical information.
B) in the worst case and when the amount of charge is very high, the
discharge process can determine failures in the electronic devices; the
type of failure can vary from an intermittently malfunction to a completely
failure of the electronic device.
U
It is always much easier and cheaper to avoid ESD from being generated,
than to increase the level of immunity of the electronic devices.
The VCM can be prone to electrostatic discharge because it is normally
connected to many command devices. These devices, which are touched by the
operator, are common sources of generation and propagation of ESD.
The best way to avoid ESD is through isolation and grounding of the propagating
devices.
It is strongly suggested to connect to truck frame all the parts of
the truck which can be touched by the operator
.
