3Com LINKBUILDER 3C18500, Руководство пользователя

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3 - 12 C
H A P T E R
3: I
N S T A L L A T I O N
DUA1850-0AAA05
If you change a module for one of a different kind (that is, a 12 port
Secure ECS module for a 12 port Secure MSH module), the
management module recognizes the difference and adopts the link
settings.
Connecting Devices for Automatic Monitoring
There are four binary status input lines available on a single 9-pin
D-type connector on the front plate of the management module. These
are general purpose, and can be used to monitor the status of any
device or detector that can switch states; for example, UPSs changing
from run to standby.
Each status line can be managed using Transcend or other generic
SNMP manager. A trap is sent to the manager whenever a transition
(high-to-low or low-to-high) is held for more than ten milliseconds.
Transitions held for less than ten milliseconds may not be detected. The
traps may be enabled and disabled from the manager. Using the status
lines gives you the ability to monitor remotely the state of the detector.
Electrically, the status inputs have certain requirements which the user
must ensure are met.
CAUTION: The external switches, to which the status lines are
connected, must be completely isolated from any external power
supply or mains voltage.
Cable used for the status lines should:
■
not exceed ten meters in length,
■
have a resistance of less than two ohms,
■
be screened to conform with RFI/EMC limits.
General purpose status input capability allows monitoring devices like
UPSs (power fail) or cabinet temperature with a thermostat, You can
devise many uses to suit your particular situation.
The pin designations of the connector are given below.