Rockwell Automation Allen-Bradley ControlLogix 1756-HSC User manual

ControlLogix High-speed
Counter Module
Catalog Number 1756-HSC
User Manual Original Instructions

2Rockwell Automation Publication 1756-UM007E-EN-P - August 2021
ControlLogix High-speed Counter Module User Manual
Important User Information
Read this document and the documents listed in the additional resources section about installation, configuration, and
operation of this equipment before you install, configure, operate, or maintain this product. Users are required to familiarize
themselves with installation and wiring instructions in addition to requirements of all applicable codes, laws, and standards.
Activities including installation, adjustments, putting into service, use, assembly, disassembly, and maintenance are required to
be carried out by suitably trained personnel in accordance with applicable code of practice.
If this equipment is used in a manner not specified by the manufacturer, the protection provided by the equipment may be
impaired.
In no event will Rockwell Automation, Inc. be responsible or liable for indirect or consequential damages resulting from the use
or application of this equipment.
The examples and diagrams in this manual are included solely for illustrative purposes. Because of the many variables and
requirements associated with any particular installation, Rockwell Automation, Inc. cannot assume responsibility or liability for
actual use based on the examples and diagrams.
No patent liability is assumed by Rockwell Automation, Inc. with respect to use of information, circuits, equipment, or software
described in this manual.
Reproduction of the contents of this manual, in whole or in part, without written permission of Rockwell Automation, Inc., is
prohibited.
Throughout this manual, when necessary, we use notes to make you aware of safety considerations.
Labels may also be on or inside the equipment to provide specific precautions.
WARNING: Identifies information about practices or circumstances that can cause an explosion in a hazardous environment, which
may lead to personal injury or death, property damage, or economic loss.
ATTENTION: Identifies information about practices or circumstances that can lead to personal injury or death, property damage,
or economic loss. Attentions help you identify a hazard, avoid a hazard, and recognize the consequence.
IMPORTANT Identifies information that is critical for successful application and understanding of the product.
SHOCK HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that dangerous voltage
may be present.
BURN HAZARD: Labels may be on or inside the equipment, for example, a drive or motor, to alert people that surfaces may reach
dangerous temperatures.
ARC FLASH HAZARD: Labels may be on or inside the equipment, for example, a motor control center, to alert people to potential Arc
Flash. Arc Flash will cause severe injury or death. Wear proper Personal Protective Equipment (PPE). Follow ALL Regulatory
requirements for safe work practices and for Personal Protective Equipment (PPE).

Rockwell Automation Publication 1756-UM007E-EN-P - August 2021 3
Table of Contents
Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Summary of Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Who Should Use This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Additional Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 1
Module Features Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
What is a High-speed Counter Module? . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Encoder and Sensor Compatibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1756-HSC Module Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Additional I/O Module Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1756-HSC Parts Illustration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Chapter 2
Counter Modes Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Counter/Encoder Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Counter Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Encoder Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Preset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Rollover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Input Z (Gate/Reset) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Storage Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Assign Outputs to Counters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Chapter 3
Frequency Modes Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Frequency Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Frequency Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Sample Period for Frequency Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Period Rate and
Continuous Rate Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Sample Period for Period/Continuous Rate Modes. . . . . . . . . . . . . . 29
Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Period Rate /Continuous Rate Output Examples . . . . . . . . . . . . . . . . . . . 32
Maximum Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

4Rockwell Automation Publication 1756-UM007E-EN-P - August 2021
Table of Contents
Chapter 4
Install and Wire the
ControlLogix High-speed
Counter Module
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Install the Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Key the Removable Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Wiring the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Connect the Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Connect Ungrounded End of the Cable . . . . . . . . . . . . . . . . . . . . . . . . 41
Two Types of RTBs (each RTB comes with housing) . . . . . . . . . . . . . 41
Recommendations for Wiring Your RTB . . . . . . . . . . . . . . . . . . . . . . . 42
Wire Terminations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Wire an Allen-Bradley 845 Incremental Encoder . . . . . . . . . . . . . . . . 42
Wire an Allen-Bradley Bulletin 872 3-Wire DC Proximity Sensor . 43
Wire a PHOTOSWITCH® Series 10,000 Photoelectric Sensor . . . . 44
Assemble the Removable Terminal Block and Housing. . . . . . . . . . . . . . 45
Install the Removable Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Remove the Removable Terminal Block . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Remove the Module from the Chassis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Chapter 5
Configure the Module Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
ControlLogix Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Direct Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Local Chassis Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Remote Chassis Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Use the Default Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Use the Programming Software, Version 18 or Later,
to Configure a Module. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Communication Format Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
Set RPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Set Up Counter Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Filter Selections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
Set Up Output Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Copy Configuration (.C) Output, Rollover, Preset Tags
to Output (.O) Tags. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
Electronic Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Exact Match. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Compatible Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Disabled Keying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
Download Configuration to the 1756-HSC Module. . . . . . . . . . . . . . . . . . 71

Rockwell Automation Publication 1756-UM007E-EN-P - August 2021 5
Table of Contents
Chapter 6
Module Diagnostics Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
1756-HSC Error Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Programming Software Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Fault Type Determination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Troubleshoot the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
Appendix A
Status Indicators Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Status Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
Appendix B
Data Structures Configuration, Output, Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Configuration Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Output Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
Input Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Appendix C
Module History Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
Profile Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
Configure a Generic Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Copy ACD file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Add Ladder Logic Routines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Upgrade Module to Software Version 18 and Later . . . . . . . . . . . . . . 92
Edit Thin Profile Tags . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
Change Configuration Data Via Message Instruction. . . . . . . . . . . . . . . 94
Appendix D
Application Considerations Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Types of Input Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
Examples for Selecting Input Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Circuit Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
Detailed Circuit Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
5V Differential Line Driver Example . . . . . . . . . . . . . . . . . . . . . . . . . . 100
+12 to +24V Single-ended Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Open Collector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102
Electromechanical Limit Switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

6Rockwell Automation Publication 1756-UM007E-EN-P - August 2021
Table of Contents
Output Circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Series A and B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Series C and D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
Application Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Input Cable Length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Totem-pole Output Devices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Cable Impedance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Cable Capacitance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Cable Length and Frequency. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

Rockwell Automation Publication 1756-UM007E-EN-P - August 2021 7
Preface
This manual describes how to install, configure, and troubleshoot your
ControlLogix® High-speed Counter (HSC) module, catalog number 1756-HSC,
herein referred to as the module.
Based on your module series and firmware revision, there are programming
software requirements to use some module features. For more information,
see Table 10 on page 83.
Summary of Changes This table contains the changes that are made to this revision of
the publication.
Who Should Use This Manual You must be able to program and operate a ControlLogix controller and
various Allen-Bradley®encoders and sensors to use your module efficiently. In
this manual, we assume that you know how to use these products. If you do
not, refer to the related user publications for each product, before you attempt
to use the module.
Additional Resources These documents provide information that is related to your module.
You can view or download publications at http://
www.rockwellautomation.com/literature. To order paper copies of technical
documentation, contact your local Allen-Bradley distributor or Rockwell
Automation sales office.
Topic Page
Updated Appendix D, Application Considerations , in the following sections:
• Circuit Overview, Series C and D Modules 97
• Detailed Circuit Analysis, Series C and D Modules 99
• +12…+24V Single-ended Driver 100
• Open Collector, Series C and D Modules 103
• Electromechanical Limit Switch 103
• Output Circuits, Series C and D Modules 105
Resource Description
1756 ControlLogix I/O Technical Data, publication 1756-TD002 Provides specifications for the ControlLogix controllers, I/O modules, specialty modules, chassis, power
supplies, and accessories.
ControlLogix System User Manual, publication 1756-UM001 Detailed description of how to use your ControlLogix
operating system.
ControlLogix Digital I/O Modules User Manual,
publication1756-UM058 Detailed description of how to install and use
ControlLogix digital I/O modules.
ControlLogix Analog I/O Modules User Manual,
publication 1756-UM009 Detailed description of how to install and use ControlLogix analog I/O modules.
RSLogix 5000® Getting Results Guide,
publication 9399-RLD300GR.Provides software installation instructions and to learn
how to navigate the software package.
Industrial Automation Wiring and Grounding Guidelines,
publication 1770-4.1 Provides general guidelines for installing a Rockwell
Automation industrial system.

8Rockwell Automation Publication 1756-UM007E-EN-P - August 2021
Preface
Notes:

Rockwell Automation Publication 1756-UM007E-EN-P - August 2021 9
Chapter 1
Module Features
Introduction The high-speed counter module performs high-speed counting for industrial
applications. This chapter provides an overview of the design and features of
the module.
What is a High-speed
Counter Module?
The module counts pulses by using a Counter or Frequency operational mode.
The counts are presented as either ‘accumulated count’ or ‘frequency’
depending on the mode that is configured for the module.
You can choose from either one of three Counter modes or one of three
Frequency modes when configuring the module. The operational mode that is
selected determines how the pulse count is stored and the behavior of the
outputs.
You can manipulate the storage of the count values (detailed in Chapter 2). The
module evaluates these count values against user configured presets and/or
values, thus the response time for activating outputs is performed at a faster
rate than evaluating in the controller.
Configuration tags, which are automatically installed with the module during
the initial download of the programming software, determine whether the
module interprets pulses as:
• accumulated count - values can be 1…16 million.
• frequency - positive or negative depending on the direction of the
rotation.

10 Rockwell Automation Publication 1756-UM007E-EN-P - August 2021
Chapter 1 Module Features
Pulse count values can be calculated by using different types of Counter and
Frequency modes. The simple counter uses only input A to count pulses. An
encoder uses both input A and input B to count pulses. The relationship
between the two channels is how the encoder determines if the count is
positive (clockwise) or negative (counterclockwise).
This user manual also details the Frequency operational modes that are
available depending on which one is required for your application. Frequency
can be calculated in one of three ways:
• frequency (rate measurement).
•periodrate.
• continuous rate.
All three Frequency modes determine the frequency of input pulses by
counting pulses over a user-defined time interval. If the revolution is spinning
in a clockwise direction, the frequency is positive; in a counterclockwise
direction it’s decreasing (negative) frequency.
See page 25 for more details on Frequency modes.
Pulse counts and frequency values are stored in one of three input tags (based
on the mode) as shown in the table.
See Data Structures in Appendix C for a list of tags.
Table 1 - Mode and Input Tag Values for the 1756-HSC Module
Comm Format = HSC Data-extended Tags
Mode Mode Description Present Value Stored Value Totalizer
0Counter
Accumulated count Stored value Directional frequency(1)
1EncoderX1
2EncoderX4
3CounterNotUsed— ——
4Frequency
(Rate Measurement)(2) No. of input pulses occurring in
sample period
Frequency
Accumulated count(3)
5Frequency
(Period Rate)(2) No. of 4 MHz pulses occurring in
sample period Accumulated count
6Frequency
(Continuous Rate)(2)
(1) B-input state defines direction (Counter mode).
(2) Modes where frequency controls the outputs.
(3) Rollover/Preset settings apply.