Micromod MOD: Remote I/O Modules for use with 2020N Remote I/O Interface Module - Manual (Page 5)

Remote I/O Modules
PRODUCT DESCRIPTION
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PRODUCT DESCRIPTION
1.1 OVERVIEW
This document describes the remote I/O module product offering, installation of the I/O
modules and their connection using the 2020N Remote I/O Interface module as a network
master. Basically, remote I/O modules feature:
• Remote digital I/O modules
• Fieldbus network to multiloop instruments with a Remote I/O Interface module
• Combine with local I/O modules for optimum process monitoring and control
Remote Input and Output Modules, Figure 1-1, expand the I/O capability of an instrument
with a 2020N Remote I/O Interface (RIO) Module by a total of 100 discrete points. The
remote I/O modules communicate with the RIO module over the Remote I/O Network. The
RIO module is not required to reside in a communications slot, leaving the instrument
communications channels open for host or peer-to-peer communications.
The Remote I/O Network is an RS-485 fieldbus, up to 500 meters (1600 feet) in length. It
connects to the terminations on the host instrument and is multidropped to the remote I/O
modules. Two wires plus shield are used for the network (shield is required over 50m). CRC
checking is provided by the network protocol.
Remote I/O may be combined with local I/O modules to provide the optimum configuration for
a given application. Process measurements requiring a higher degree of resolution, or
critical control loops, can be implemented using the single-point isolated local I/O modules.
Figure 1-1. Remote I/O Module Installation
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