Omega Vehicle Security OMP-MODL - Manual (Page 59)

3... I NTERFACE M ODULES
U SING THE OMP-MODL 3-35
Frequency Signal Connection:
To utilize an MLIM-2 channel as a Frequency input, connect the input signal
positive lead to one of the four Input terminals (Chan A, B, C, or D) and the
negative lead to one of the four Common terminals on the module terminal
strip (Figure 3... -23). Note that all of the four Common terminals 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 four channels of the MLIM-
2 (
Figure 3... -22). When connecting to multiple frequency
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 frequency signal and possible damage to the
MLIM-2.
For Frequency recording applications with small signal amplitude, high
frequencies, long lead length and/or in noisy environments, twisted pair wire
will provide extra noise immunity. In extremely noisy applications, shielded
wire may be required. If shielded wire is used, the shield at the OMP-MODL
end should be connected to an external earth ground (Figure 3... -23) or if
available, a grounded Shield connection provided on another type installed
interface module (such as the MLIM-1).
NOTE: Do not ground the shield wire at the end away from the OMP-MODL.
Terminal Strip
Earth Ground
ML060
+
-
Shielded Twisted
Pair Lead
Shield
+
-
Channel A Channel B Common Channel C Channel D
Frequency
Source A
Frequency
Source B
1 2 3 4 5 6
Figure 3... -23: Frequency input terminal strip connections (two inputs shown)