Rockwell Automation 1746-NI8 SLC 500 Analog Input Modules User Manual - Manual (Page 11)

Chapter
1
Publication 1746Ć6.8 - April 1997
Overview
This chapter describes the 1746-NI8 analog input module and
explains how the SLC 500
t processor gathers analog input from the
module. Included is information about:
•
the module’s hardware and diagnostic features
•
an overview of system operation
The module receives and stores digitally converted analog data into
its image table for retrieval by all fixed and modular SLC 500
processors. The module supports connections from any combination
of up to eight voltage or current analog sensors.
The 1746-NI8 is a multiclass (Class 1 or Class 3) single-slot module.
Class 1
➀
configuration utilizes 8 input words and 8 output words.
Class 3 configuration utilizes 16 input words and 12 output words.
Fixed and SLC 5/01
t processors can only operate as Class 1. The
SLC 5/02
t, SLC 5/03t, and SLC 5/04t processors can be
configured for either Class 1 or Class 3.
The 8 high-impedance input channels can be wired as either
single-ended or differential inputs. The module provides a direct
interface to the following input types:
•
" 10V dc
•
1–5V dc
•
0–5V dc
•
0–10V dc
•
0–20 mA
•
4–20 mA
•
" 20 mA
•
0–1 mA
The data presented to the processor can be configured as:
•
Engineering Units
•
Scaled-for-PID
•
Proportional Counts (–32,768 to +32,767 range)
•
Proportional Counts with User Defined Range (Class 3 only)
•
1746-NI4 Data Format
➀
Requires use of Block Transfer in a remote configuration.
Each input channel also provides open-circuit, out-of-range, and
invalid configuration indication via the LEDs. In Class 3 operation
these conditions are also in the channel status word.
General Description