Omega Vehicle Security OMP-MODL manual MLIM-1 DC Current MA-LO Application

3... INTERFACE MODULES

APPLICATION NOTES; DC Voltage Channels

Channel Isolation:

The negative terminal of MLIM-1 channels configured as DC Voltage inputs are isolated from the OMP-MODL circuit ground by a 22Kohm resistor (see Figure 3... -12).

Common Mode Input Range Considerations:

To prevent saturation of the input amplifier stages and erroneous readings, no voltages should be applied to any input terminals that are greater than 4.0V above or below circuit ground. If the signal being measured is not connected to the OMP-MODL circuit ground (ie `isolated’ supplies are used), common mode input voltages up to 32 V can be accepted. Voltages above this level can be lethal and should not be applied to the OMP-MODL. Supply isolation can be achieved by allowing the OMP-MODL to run from its internal batteries (rather than an external source).

Multiple Measurement Nodes on a Circuit:

When measuring different voltage points from a common circuit with multiple channels (of one or more Interface Modules), measurement errors from induced ground currents can exist. Single ended measurements may be required. Consult the factory for application assistance.

MLIM-1; DC CURRENT (MA-LO) APPLICATION

The MLIM-1 can accept DC Current within the ranges specified in Table 3... -3. To utilize an MLIM-1 channel as a DC Current input, set that channel’s Configuration Switch per Table 3... -4 as a mA-LOChannel.

As shown in Figure 3... -12, when mA-DC is selected with the hardware

mA-Lo Icon Configuration Switches, a precision 100 ohm burden resistor is enabled. The input signal is measured as a voltage across the shunt resistor.

TIP: For best accuracy and absolute resolution, utilize the lowest range possible that will cover the input signal’s dynamic range without over-ranging.

Signal Connection (all Current Ranges):

Interface Module channels configured as mA-LO inputs provide three terminal strip connections per input; Positive lead, Negative lead, and Shield.

Connect the mADC signal positive and negative leads to the correct pair of terminals on the module terminal strip (Figure 3... -16).

Refer to Chapter 7; HyperNet Programming for steps to generate a

Terminal Strip Wiring printout for use in making field wiring connections.

Observe polarity or the output signal will be reversed.

USING THE OMP-MODL 3-27