A-B 1746-NT4 Module Rockwell SLC 4 Input Control

In this example:

• the controllers produce and consume tags amongst themselves.

• the controllers initiate MSG instructions that send and receive data or configure devices.

• the personal computer uploads or downloads projects to the controllers.

• the personal computer configures devices on an EtherNet/IP network.

Module Outputs

The BTM module sends the control variable (CV) for heating and/or

cooling each loop to the SLC processor’s input image table as both of:

• numeric value (current CV)

• time–proportioned output (TPO)

Temperature Control Using a BTM Module in an SLC System

The temperature control module is an intelligent I/O module that can

provide a maximum of 4 PID loops for temperature control. 

The module has 4 analog thermocouple (TC) inputs. Each analog input functions as the process variable (PV) for a PID loop. 

The PID algorithm and tuning–assisted–process (TAP) algorithm are performed on the module for each of the loops. 

The control–variable (CV) output of each loop, either analog output or time–proportioned output (TPO), is sent from the module to the SLC data table. 

Your application ladder logic must access the CV value in the data table and send the analog or TPO data to an output module to close the loop.

Features of the Temperature Control Module

The 1746–BTM module provides:

• 4 independent temperature control loops

• autotune PID loops (one loop or any combination of loops can be autotuned while other loops are running)

• a unique start–up algorithm to minimize overshoot

• an isolated thermocouple (J and K) input for each PID loop

• 16–bit analog–to–digital converter resolution (0.1° resolution)

• a heat CV signal (for each PID loop) as a numeric % value

• a cool CV signal (for each PID loop) as a numeric % value

• a heat CV signal (for each PID loop) as a TPO bit

• a cool CV signal (for each PID loop) as a TPO bit

• temperature values in C ° or F °

• self–calibration (external reference required)

• user–selectable high and low alarms with dead band for hysteresis

• input open–circuit detection

Current CV

Your ladder logic should read the numeric value (current CV), scale it,

and send it to an analog output module to generate the control signal

to an analog temperature control actuator. If using the sample

program look for current CVs in N10:208–211 for loops 1–4. 

TPO

The module returns the heat TPO (bit 6) and cool TPO (bit 7) in input

image table words 8–11 for loops 1–4. The sample program sends

TPO signals to a digital output module to generate the control signal

to a digital temperature control actuator.

A-B 1756-OB32 module Rockwell ControlLogix 32 digital output

A-B 1756-OB8 module Rockwell ControlLogix 8 digital output

A-B 1756-OB8EI module Rockwell ControlLogix 8 digital output

A-B 1756-OB8I module Rockwell ControlLogix 8 digital output

A-B 1756-OC8 module Rockwell ControlLogix 8 digital output

A-B 1756-OF4 module Rockwell ControlLogix 4 analog

A-B 1756-OF6CI module Rockwell ControlLogix 6 analog

A-B 1756-OF6VI module Rockwell ControlLogix 6 analog

A-B 1756-OF8 module Rockwell ControlLogix 8 analog

A-B 1756-OF8H module Rockwell ControlLogix 8 analog

A-B 1756-OG16 module Rockwell ControlLogix 16 digital output

A-B 1756-OH8I module Rockwell ControlLogix 8 digital output

A-B 1756-ON8 module Rockwell ControlLogix 8 digital output

A-B 1756-OV16E module Rockwell ControlLogix 16 digital output

A-B 1756-OV32E module Rockwell ControlLogix 32 digital output

A-B 1756-OW16I module Rockwell ControlLogix 16 digital output

A-B 1756-OX8I module Rockwell ControlLogix 8 digital output

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A-B 1756-PC75 Module Rockwell ControlLogix DC Power Supply

A-B 1756-PH75 Module Rockwell ControlLogix DC Power Supply

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