Mettler Toledo IND560x Guide D'installation page 66

In the panel-mount enclosure, the Discrete I/O option installs above the main board onto three fixed,
pre-installed brass standoffs secured with screws as shown in Figure 3-36 and Figure 3-36.
There are two removable 4-position terminal strips on this option board that provide connections to
the inputs and three removable 4-position terminal strips which provide connections to the outputs.
These connections are described next. Note that only the wiring connections are shown and not all
sealing or other protective methods required for safe operation. All installations must be correct per
the local wiring code and must follow the entity approval concept.
3.4.2.1. Active Inputs
Using the Discrete I/O option with active inputs enables connection of switches or other simple
devices to trigger an input. The terminal provides the intrinsically safe voltage internally making the
input active and no voltage is supplied by the external simple device.
Because the voltage supplied by the IND560x for the active inputs is intrinsically safe, the external
simple device/switch does not need to be certified for use in intrinsically safe circuits located in
hazardous gas environments.
316061929 | 12 | 01/2019
Figure 3-35: Panel-mount Enclosure Discrete I/O Installation
Figure 3-36: Panel-mount Enclosure Discrete I/O Installation
ATEX Guideline for Connection to Active Input: As a simple equipment, according the §5.7
EN/IEC 60079-11 the external simple device does not need to be certified for use in Intrinsically
Safe circuits installed inside hazardous gas environments.
METTLER TOLEDO IND560x Terminal Installation Manual 3-27