Category: A-B

Module Operation

Each input channel consists of an RTD connection, which provides:

· excitation current

· a sense connection, which detects lead-wire resistance

· a return connection, which reads the RTD or resistance value

Each of these analog inputs are multiplexed to an analog converter.

The A/D converter cycles between reading the RTD or resistance value, the

lead wire resistance, and the excitation current. From these readings, an

accurate temperature or resistance is returned to the user program.

The RTD module is isolated from the chassis backplane and chassis ground.

The isolation is limited to 500V ac. Optocouplers are used to communicate

across the isolation barrier. Channel-to-channel common-mode isolation is

limited to ± 5 volts.

LED Status

The illustration below shows the RTD module LED panel consisting of nine

LEDs. The state of the LEDs (for example, off, on, or flashing) depends on the

operational state of the module (see table on page 1-9).

System Operation

The RTD module has 3 operational states:

· power-up

· module operation

· error (module error and channel error)Power-up

At power-up, the RTD module checks its internal circuits, memory, and basic

functions via hardware and software diagnostics. During this time, the module

status LED remains off, and the channel status LEDs are turned on. If no

faults are found during the power-up diagnostics, the module status LED is

turned on, and the channel status LEDs are turned off.

After power-up checks are complete, the RTD module waits for valid channel

configuration data from your SLC ladder logic program (channel status LEDs

off). After configuration data is written to one or more channel configuration

words and their channel enable bits are set by the user program, the channel

status LEDs go on and the module continuously converts the RTD or

resistance input to a value within the range you selected for the enabled

channels. The module is now operating in its normal state.

Each time a channel is read by the module, that data value is tested by the

module for a fault condition, for example, open-circuit, short-circuit, overrange,

and under range. If such a condition is detected, a unique bit is set in

the channel status word and the channel status LED flashes, indicating a

channel error condition.

The SLC processor reads the converted RTD or resistance data from the

module at the end of the program scan or when commanded by the ladder

program. The processor and RTD module determine that the backplane data

transfer was made without error and the data is used in your ladder program.

Overview

This chapter describes the 8-channel 1746-NR8 RTD/Resistance Input

Module and explains how the SLC controller gathers RTD (Resistance

Temperature Detector) temperature or resistance-initiated analog input from

the module. Included is:

· a general description of the module’s hardware and software features

· an overview of system operation

For the rest of the manual, the 1746-NR8 RTD/Resistance Input Module is

referred to as simply the RTD module.

The RTD module receives and stores digitally converted analog data from

RTDs or other resistance inputs such as potentiometers into its image table for

retrieval by all fixed and modular SLC 500 processors. An RTD consists of a

temperature-sensing element connected by 2. 3. or 4 wires that provide input

to the RTD module. The module supports connections from any combination

of up to eight RTDs of various types (for example: platinum, nickel, copper, or

nickel-iron) or other resistance inputs.

Description

The RTD module supplies a small current to each RTD connected to the

module inputs (up to 8 input channels). The module provides on-board

scaling and converts RTD input to temperature (°C, °F) or reports resistance

input in ohms.

Each input channel is individually configurable for a specific input device.

Broken sensor detection (open- or short-circuit) is provided for each input

channel. In addition, the module provides indication if the input signal is

out-of-range. For more detail on module functionality, refer to the subsection

entitled System Overview later in this chapter.

Description

The RTD module receives and stores digitally converted analog data

from RTD units or other resistance inputs such as potentiometers into

its image table for retrieval by all fixed and modular SLC 500

processors. An RTD module consists of a temperature-sensing element

connected by two, three, or four wires that provide input to the RTD

module. The module supports connections from any combination of

up to four RTD units of various types (for example: platinum, nickel,

copper, or nickel-iron) or other resistance inputs.

The RTD module supplies a small current to each RTD unit connected

to the module inputs (up to 4 input channels). The module provides

on-board scaling and converts RTD unit input to temperature (°C, °F)

or reports resistance input in ohms.

Each input channel is individually configurable for a specific input

device. Broken sensor detection (open- or short-circuit) is provided

for each input channel. In addition, the module provides indication if

the input signal is out-of-range.

Overview

The 1746-N3 Connector Kit is used to terminate a cable which connects field I/O 

devices to SLC 500 32-point I/O modules. The kit contains a keyed 40-pin socket 

header with 45 socket crimp type contacts.

The N3 connector is compatible with 32-point I/O modules, catalog numbers 

1746-IB32, -IV32, -OB32, -OB32E -OV32 and Allen-Bradley 1492-IFM40 terminal 

blocks (see illustration). When the 1746-N3 is used to terminate the I/O cable at the 

1492-IFM40 end, it should be wired in a straight-through manner (i.e. pin 1 to pin 1, 

pin 2 to pin 2, etc.). For additional instructions, refer to the wiring instructions 

provided with your 32-point I/O module.

Use 24 AWG wire with the 1746-N3. Maximum wire length to the user terminal 

block is 10 meters for inputs and 3 meters for outputs with 7-strand, 24 AWG wire.

Assembly Procedure for Crimp Contacts

The following details the assembly procedure for the crimp type contacts.

1. Strip the wire insulation as shown in Figure 1.

2. Insert the wire up to the wire stop as shown in Figure 2.

3. Crimp with DDK crimp tool 357J-5538. Equivalent Amp part numbers are: 

pin – 87666-2, connector – 102387-9, and crimp tool – 90418-1.

If a crimp tool is not available, used the following crimping procedure:

a. Crimp the wire barrel around the wire using a small needle nose pliers.

b. Crimp the insulation barrel around the wire insulation using a small 

needle nose pliers.

c. Solder wire and wire barrel together.

4. After completing above assembly, insert the cable into the socket housing as 

shown in Figures 3 and 4. Check to make sure that the tang, shown as “A” in 

Figure 4, is properly latched by gently pulling on the wire.

What the module does

The module processes and extracts cyclic injection molding data for 

display on your PC, and responds to alarms that you set to monitor 

critical molding parameters. 

When used with the Pro-Set 200 Injection Molding Control System, 

the module helps you:

• achieve a quicker setup time to obtain optimum part quality

• maintain that quality over the production run

The module and associated DARTWin software help you to set up the 

injection molding machine for optimum performance. Then you set 

alarm limits on critical parameters to detect deviations while making 

parts. You can also set a critical mold pressure to transfer the injection 

process each machine cycle. 

The module is designed for use with the SLC 5/03 (or later) processor. 

You program it to interface with the injection molding machine. The 

module has two independent channels to accept analog pressure inputs 

from sensors or from the SLC processor across the backplane. It 

returns alarm signals and processed molding parameters to the SLC 

processor for your application programming and to your PC for 

graphic display. We show the module in a typical Pro-Set 200 system.

Wiring Notes

• Ground cable shields at one end only.

• Isolate signal wiring from power lines and sources of electrical noise.

• Do not exceed 10V dc on any input terminal.

• Outputs +Exc, +T/R, and -T/R must have a minimum load of 1K ohms.

referenced to analog common.

Features and Benefits

Select I/O modules to exactly match your application. 

Combinationmodules allow you to have inputs and outputs in a single slot for efficient use of your chassis space.

Expand the I/O capacity of your fixed controller system. 

Two discrete I/O modules can be added to the fixed controller’s 2-slot expansion

chassis increasing the flexibility of the system.

All relay contacts are Silver Cadmium with Gold overlay. 

Gold plating resists oxidation and tarnishing resulting from non-use.

Silver Cadmium acts as an excellent conductor.

High-density 32-Point DC I/O and fast response DC inputs are available.

These modules allow you to apply the SLC 500 processors in a broader spectrum of control applications.

LEDs indicate the status of each I/O point. 

Assisting you in troubleshooting, LEDs illuminate when the proper signal is received

at an input terminal, or when the processor applies power to an output terminal.

Terminal identification diagrams on each module. 

Terminal identification diagrams are located on each module making terminal

identification easier.

Description

The Allen-Bradley 1746-HSTP1 is a stepper controller module. 

A single-slotted module capable of operating a wide variety of SLC 500 series processors. 

With a differential encoder motion that is programmable for more than 8.000.000 counts of absolute position.

The 1746-HSTP1’s feedback hardware adapts up to 250 kHz of any frequencies. 

It can provide 250 kHz pulse train output for micro-stepping applications. 

It uses loopback diagnostics and differential incremental encoder feedback devices. 

The 1746-HSTP1 provides a differential feedback that interfaces directly to +5 or +15 V encoders. 

The module has a 5″ x 2″ x 6″ (13 cm x 5 cm x 15 cm) estimated dimension and weighs 15 oz (0.43 kg) approximately. 

Programmable modes of operation reduce the need for setting a DIP switch.

The 1746-HSTP1 module has a 200 mA back-plane current at 5 volts and 90 mA at 24 volts. 

It has a 5V DC differential encoder or 12-24V DC single-ended auxiliary inputs. 

It provides a digital output for the translator with a 4 ms module update time. 

The controller module has a 7 – 30 mA at 5V DV pulse train switching. 

This stepper controller module interface directly to encoders with differential feedback with +5 or +15V signal. 

It is also compatible with transistors with differential input translators, single-ended TTL and interface for opto-couplers.

This module does not include DIP switches for setting and configuration.

The module provides quick operational diagnostics through its embedded LED indicators that provide feedback regarding programming errors, 

normal and abnormal operation and a faulted system. 

This module also has built-in loop diagnostics that monitors the pulse train commands provides to the module’s translator.

Use the table below to find the current requirements of the devices 

using backplane power. Those devices that are not included in the 

backplane calculations are included in the example’s user-side calculations.

Selecting a User-Side Power Supply

You must provide a power supply that meets your system 

requirements. The following devices require user-side power:

• SLC Servo Module

• Encoders

• I/O modules

• Estop circuitry

• Fast inputs and outputs

You must select a power supply that meets the specifications of a NEC 

class 2 power supply. The power supply must have +5V, ±15V 

capacity, and +24V capacity for fast I/O and Estop circuitry.

Example of the Calculations for User-Side Current Requirements 

In this example, the system includes:

• One seven-slot modular rack

• One 1747-L541 CPU module

• One 1746-IB8 DC input module with eight inputs @ +24V

• One 1746-OV8 DC output module with eight outputs @ +24V

• An SLC Servo Module system that contains:

• Two SLC Servo Modules

• Two termination panels

• Two Allen-Bradley 845H encoders

• Six fast inputs

• Two fast outputs

Using Fast Inputs and Outputs

The fast I/O (FIN1through FIN3, and FOUT1) are 24V DC compatible 

and are used with a user-side +24V power supply. Review potential

24V DC I/O devices for compatibility with the electrical specifications 

as shown in the table below.

SLC Servo Module Operation

The SLC Servo Module, compatible with the SLC family, is used with 

SLC 5/03 FRN 5.0 (and above) processors using RSLogix 500, AI500 or 

APS (version 5.0 or higher) software. Once the SLC processor is 

initiated, the execution of the motion block is independent of the scan 

time of the processor. Blended motion allows for complicated move 

profiles consisting of two to thirty-two segments. The blended move 

profiles are stored in the SLC Servo Module’s memory as a series of 

absolute moves and can be executed more than once. Other move or 

homing operations can be performed between blended move profiles.

The SLC Servo Module controls absolute position over a range of 32 

bits. The SLC Servo Module performs an origin search (also called 

homing) and automatically resets the absolute position to the home 

position when the SLC processor requests a search function after 

detecting one of the following: 

• Encoder marker

• Limit switch

• Limit switch and marker

The SLC Servo Module operates in two modes:

• Configuration 

• Command 

When operating in the configuration or the command mode, the status 

of the module is reported to the SLC processor.