Omega OMP-MODL, User Manual

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3... I
NTERFACE
M
ODULES
U
SING
T
HE
OMP-MODL 3-50
negative lead to one of the four Common terminals on the module terminal
strip (Figure 3... -33). Note that all of the four Common terminals on the
terminal strip (3, 6, 9, 12) are interconnected and connect directly to the
OMP-MODL circuit ground. Refer to Chapter 7 for steps to generate a
Terminal Strip Wiring printout for use in making field wiring connections.
CAUTION: Note that a direct connection exists between
the common (-) terminal on all eight channels of the
MLIM-8. When connecting to multiple event signal
sources sharing a common ground or reference, insure
that the source’s ground or reference is connected to the
terminal strip `common’ terminal to prevent shorting out
of the source signal and possible damage to the MLIM-8.
For most event applications, shielding is not necessary due to the relatively
low input impedance of the channel and the high noise immunity of the
MLIM-8 channel input.
MLIM-8; D
IGITAL
O
UTPUT
A
PPLICATION
An MLIM-8 channel configured as a Digital Output can provide an ON/OFF voltage
signal for alarming applications. The output is a current limited voltage signal with
the approximate voltage/current characteristics shown in Figure 3... -34. As shown,
with a light load, the output voltage maintains approximately 4+ VDC but as the
current draw increases, current limiting occurs and the output voltage droops. The
output can be short circuited continuously without damage to the output drive
circuitry, but the OMP-MODL battery life will be correspondingly reduced.
5
4
3
2
1
0
0 3 6 9 12 15
Current (milliAmps)
Voltage
HL033
Figure 3... -34: MLIM-8 Digital output drive characteristics
Digital
Output icon
(MLIM-8)