Mettler Toledo IND780 Manuel D'installation page 61

Figure 2-52: Example of Active Input from Switches
Passive Input
Selecting the inputs as passive enables other devices such as PLCs to provide the
trigger voltage (typically 24 VDC, 5-30 VDC) to turn the IND780 inputs "on". An
example of wiring to the passive inputs is shown in Figure 2-53. The voltage
polarity may be reversed. Furthermore, inputs can be programmed in SETUP to
accept either a + True or – True polarity level as "ON".
Note – The voltage source
must be a Class 2
marked or a Limited
Power Source (LPS)-
compliant power supply
Figure 2-53: Example of Passive Input from Discrete Output Device
IND780 Installation Manual
2-33