Module overview, Chapter 1 – Spectrum Controls 1756sc-OF8H Series A User Manual
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Module Overview
This chapter describes the functionality of the modules and explains how
the ControlLogix controller reads/writes analog data from the modules and
how HART data is derived from the modules. Read this chapter to
familiarize yourself further with your analog module. This chapter covers:
• general description and hardware features
• an overview of system and module operation
General Description
This module is designed exclusively for use in the Allen-Bradley
ControlLogix 1756 I/O rack systems. The HART input module, 1756sc-
IF8H, stores digitally converted volt (V) and milliamp (mA) analog data
and HART field instrument data in its image table for retrieval by all
ControlLogix processors. The HART output module, 1756sc-OF8H,
produces voltage or current output for control and maintains a dialog with
HART-compatible field instruments
Following is a list of features available on the IF8H and OF8H modules
that allow their use in a wide variety of applications.
· Removal and insertion under power (RIUP) - a system feature that
allows you to remove and insert modules while chassis power is applied
· Producer/consumer communications - an intelligent data exchange
between modules and other system devices in which each module
produces data without having been polled
· Rolling time stamp of data - 15 bit module-specific rolling timestamp with
millisecond resolution which indicates when data was sampled/applied.
This timestamp may be used to calculate the interval between channel
updates.
· System timestamp of data - 64 bit system clock places a timestamp on
the transfer of data between the module and its owner controller within
the local chassis
· IEEE 32 bit floating point format
· On-Board Features, such as custom User Scaling, Process Alarms, Rate
Alarms, Digital Filtering, and Under/Overrange Detection
· User Calibration - analog I/O modules may be calibrated by the user to
accommodate application related errors.
· Class I/Division 2, UL, CSA, CE, and FM Agency Certification
Chapter 1