![Focal 922-MES Скачать руководство пользователя страница 26](http://html1.mh-extra.com/html/focal/922-mes/922-mes_user-manual_2313663026.webp)
Model 922-MES
– User Manual
Focal Technologies Corporation
Page 6-7
A Moog Inc. Company
Document No. 922-0662-00, Rev 1.0
6.8.3 Isolation and Grounding
A “chassis ground” is provided on the printed circuit board for EMC and ESD performance. It is accessible via
eight mounting holes, as shown in the figure below, and may be connected to a metal enclosure or mounting
plate with appropriate conductive hardware. As the card is not intended for use with primary circuits or other
hazardous voltages, the chassis node is a functional earthing point and is not intended as a protective earth
(PE) terminal.
The two isolated mounting holes on the 96-pin DIN connector are intended solely for mechanical support. If
required these two holes can be accessed by removing the existing connector mounting hardware. The five
mounting holes “A” close to the DIN connector are normally used to hold a heat plate in place. If required these
five holes can also be accessed by reconfiguring the heat plate hardware. Please consult the factory for
recommendations.
Figure 6-6: Mounting Holes Locations
Reference (REF) lines are provided with each copper port and may be used as shield reference connections for
shielded twisted pair (STP) cabling. Typically, unshielded twisted pair (UTP) cabling should be used, such as
Cat 5e or better. If STP cabling is required, shields may need to be terminated and connected to the enclosure
entry point. Note that the REF lines are connected to chassis through a parallel capacitor and 10
MΩ bleed
resistor.
The 922-MES is intended for use with SELV rated power supplies and Ethernet Environment A, as defined by
IEEE 802.3 section 27.5.3. Extension of copper Ethernet segments that cross Environment B boundaries may
require additional isolation or use of the optical links for such connections. Note that the 24 VDC power lines
VIN+ and VIN-, are isolated from chassis.
MOUNTING HOLES: A
(CHASSIS CONNECTION)
A
A
A
A
A
A
A
A
CONNECTOR
MOUNTING
HOLES
(ISOLATED)