OPTO 22 SNAP PAC SNAP-IT-PM Series, Руководство по установке

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CHAPTER 1: SNAP PAC SNAP-IT-PM INSTALLATION GUIDE
Form 1698-070427—SNAP PAC SNAP-IT-PM Installation Guide 3
3
Quick Start
The following diagram shows the parts inside the SNAP-IT unit and wiring for attaching external AC
power.
About Modules
Input/output (I/O) modules are sold separately from the SNAP-IT unit so you can choose the
modules you need from the wide variety available. Modules come in four basic types:
• Digital modules monitor or control electrical, mechanical, and electronic devices that can be
in one of only two states: either on or off. Dry contacts and door sensors are examples of digital
devices. Four-channel modules each have four points; high-density digital modules have more
than four points, usually 16 or 32. These points are used either as inputs to report a device’s
on/off status, or as outputs to turn a device on and off remotely.
• Analog modules monitor or control devices that have a range of possible values, such as
temperature or pressure sensors. Analog modules contain 1 to 32 input or output points.
G N L
24 VOLT LOOP SUPPLY
– – + +
G N L
100 V 250 V
SNAP PAC controller
or brain
Rack I/O module connectors
External power
connection
NOTE: Power supplies are located behind the panel.