Mettler Toledo IND780 Manual De Instalación página 59

6. For an IND780 panel mount enclosure, make the terminations described in
step 5 to the external ground stud indicated in Figure 2-48.
Inner drain wire
and power
ground wire
Panel enclosure
grounding stud
Figure 2-48: Completed PDX Home Run Power Ground Connection,
Open Collector Output
The PDX option board provides a single TTL-compatible open collector output (pin
1 and pin 2), with current sinking components that can handle from 5 to 30 VDC
signals at a maximum of 35 mA current. A solid state relay or OPTO 22 is typically
connected to buffer the output to a 120 or 220 VAC signal. The voltage source
must be a Class 2 marked or a Limited Power Source (LPS)-compliant power
supply.
This output is reserved for use with the scale's material transfer target functionality.
It provides the feed output signal associated with the active target for a PDX scale
assigned as scale 1.
Discrete I/O (Input/Output) Connections
The relay output version of the Discrete I/O option provides four isolated inputs and
four dry-contact, normally open relay outputs. The inputs can be selected as either
active or passive based on the position of the slide switch on the board.
Figure 2-49 and shows a Discrete I/O board in its Solid State Relay configuration,
and Figure 2-50 the Relay version.
IND780 Installation Manual
Panel Mount Enclosure
Ground wire
connected to pin
7 of PDX option
board
2-31