Rockwell Automation 6181X-12TPXPDC Industrial Integrated Computers for Hazardous Locations - Manual (Page 16)

16 Rockwell Automation Publication 6181X-UM001B-EN-P - May 2011
Chapter 2 Installation
Control Drawing - Class I Division 2 and Zone 2 Required Circuit
Parameters for USB Peripheral Devices
The following control drawing is provided in accordance with the National
Electrical Code, Article 500 (Class I, Zone 2, Group IIB and Class I, Division 2,
Groups A, B, C, and D).
Application Information
The circuit parameters of associated field-wired apparatus for use in hazardous
locations shall be coordinated with the host product such that their combination
remains nonincendive. The 6181X computers and the USB peripheral devices
shall be treated in this manner.
The circuit parameters of the 6181X computers’ USB ports are indicated in the
previous table. The 6181X computers provides four separately powered USB ports.
Parameter Value Parameter Definition
V
oc (USB)
5.25V DC Open circuit voltage of each host USB port.
The maximum applied voltage rating, V
max (peripheral)
, of each
peripheral device shall be greater than or equal to V
oc (USB)
.
V
max (peripheral)
³ V
OC (USB), as appropriate
I
sc (USB)
950 mA Maximum output current of each host USB port.
The maximum current, I
max (peripheral)
, to which each USB peripheral
device can be subjected shall be greater than or equal to I
sc
(USB) .
I
max (peripheral)
³ I
sc (USB)
C
a (USB)
20 µF This value is the maximum total capacitance that can be connected
to each USB port. The total capacitance of each USB peripheral and
its cable must not exceed the indicated value.
The maximum total capacitance, C
i (peripheral),
and cable capacitance
of each separate USB peripheral device shall be less than or equal
to C
a (USB)
.
C
i ( peripheral)
+ C
cable
£ C
a (USB)
L
a (USB)
3.11 µH This value is the maximum total inductance that can be connected
to each USB port. The total inductance of each peripheral device
and its cable must not exceed the the indicated value.
The maximum total inductance, L
i (peripheral),
and cable inductance
of each separate USB peripheral device shall be less than or equal
to L
a (USB).
L
i (peripheral)
+ L
cable
£ L
a (USB)
USB Port USB Peripheral Device
USB Port USB Peripheral Device
USB Port USB Peripheral Device
USB Port USB Peripheral Device
6181X Host Product
Associated Nonincendive
Field Wiring Apparatus Nonincendive Field
Wiring Apparatus