Proface PS4800 - 19 Panel PC" - Manual (Page 60)

Industrial Personal Computer Connections
60
The following figure shows the USB cable wiring:
Notes:
1. The following table gives the Non-incendive Circuit Parameters:
The Entity Concept allows interconnection of non-incendive apparatus with
associated apparatus – not specifically examined combinations – as a system when
the approved values of V
oc
(or U
o
) and I
sc
(or I
o
) for the associated apparatus are
less than or equal to Vmax (U
i
) and Imax (I
i
) for the non-incendive apparatus, and
the approved values of C
a
(C
o
) and L
a
(L
o
) for the associated apparatus are greater
than or equal to C
i
+ C
cable
and L
i
+ L
cable
, respectively, for the non-incendive field
wiring apparatus.
2. Associated Non-incendive Field Wiring Apparatus shall satisfy the following:
3. If the electrical parameters of the cable are unknown, the following values may be
used:
z C
cable
= 196.85 pF/m (60 pF/ft)
z L
cable
= 0.656
µH/m (0.20 µH/ft)
4. Wiring methods must be in accordance with the electrical code of the country in
use.
The Industrial Personal Computer must be installed in an enclosure. If installed in a
Class I, Division 2 Location, the enclosure must be capable of accepting one or
more Division 2 wiring methods.
Circuit Parameters USB port 1 USB port 2 USB port 3
Open-circuit voltage = V
oc
5.107 V 5.119 V 5.107 V
Short-circuit current = I
sc
1029 mA 1029 mA 1273 mA
Associated
capacitance = C
a
20
µF
20
µF
20
µF
Associated inductance = L
a
16.8
µH
16.8
µH
16.8
µH
Industrial Personal Computer - Associated Non-incendive Field Wiring
Apparatus (Mouse, Keyboard)
V
oc
I
sc
C
a
L
a
≤
≤
≥
≥
V
max
I
max
C
i
+ C
cable
L
i
+ L
cable