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SNAP PAC BRAINS USER’S GUIDE
SNAP-PAC-EB1
SNAP-PAC-EB2
Form 1690-070504—May 2007
43044 Business Park Drive • Temecula • CA 92590-3614
Phone: 800-321-OPTO (6786) or 951-695-3000
Fax: 800-832-OPTO (6786) or 951-695-2712
www.opto22.com
Product Support Services
800-TEK-OPTO (835-6786) or 951-695-3080
Fax: 951-695-3017
Email: support@opto22.com
Web: support.opto22.com
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SNAP PAC Brains User’s Guide
Form 1690-070504—May 2007
Copyright © 2007 Opto 22.
All rights reserved.
Printed in the United States of America.
The information in this manual has been checked carefully and is believed to be accurate; however, Opto 22 assumes no
responsibility for possible inaccuracies or omissions. Specifications are subject to change without notice.
Opto 22 warrants all of its products to be free from defects in material or workmanship for 30 months from the
manufacturing date code. This warranty is limited to the original cost of the unit only and does not cover installation, labor, or
any other contingent costs. Opto 22 I/O modules and solid-state relays with date codes of 1/96 or later are guaranteed for life.
This lifetime warranty excludes reed relay, SNAP serial communication modules, SNAP PID modules, and modules that
contain mechanical contacts or switches. Opto 22 does not warrant any product, components, or parts not manufactured by
Opto 22; for these items, the warranty from the original manufacturer applies. These products include, but are not limited to,
OptoTerminal-G70, OptoTerminal-G75, and Sony Ericsson GT-48; see the product data sheet for specific warranty
information. Refer to Opto 22 form number 1042 for complete warranty information.
Cyrano, Opto 22 FactoryFloor, Optomux, and Pamux are registered trademarks of Opto 22. Generation 4, ioControl, ioDisplay,
ioManager, ioProject, ioUtilities, mistic, Nvio, Nvio.net Web Portal, OptoConnect, OptoControl, OptoDataLink, OptoDisplay,
OptoOPCServer, OptoScript, OptoServer, OptoTerminal, OptoUtilities, PAC Control, PAC Display, PAC Manager, PAC Project,
SNAP Ethernet I/O, SNAP I/O, SNAP OEM I/O, SNAP PAC System, SNAP Simple I/O, SNAP Ultimate I/O, and SNAP Wireless LAN
I/O are trademarks of Opto 22.
ActiveX, JScript, Microsoft, MS-DOS, VBScript, Visual Basic, Visual C++, and Windows are either registered trademarks or
trademarks of Microsoft Corporation in the United States and other countries. Linux is a registered trademark of Linus
Torvalds. Unicenter is a registered trademark of Computer Associates International, Inc. ARCNET is a registered trademark of
Datapoint Corporation. Modbus is a registered trademark of Schneider Electric. Wiegand is a registered trademark of Sensor
Engineering Corporation. Nokia, Nokia M2M Platform, Nokia M2M Gateway Software, and Nokia 31 GSM Connectivity
Terminal are trademarks or registered trademarks of Nokia Corporation. Sony is a trademark of Sony Corporation. Ericsson is a
trademark of Telefonaktiebolaget LM Ericsson.
All other brand or product names are trademarks or registered trademarks of their respective companies or organizations.
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SNAP PAC Brains User’s Guide
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Table of Contents
Chapter 1: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
About SNAP PAC Brains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
I/O Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
PAC Project Software Suite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Other Communication Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
About this Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Other Documents You May Need . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
For Help . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Chapter 2: Installing a SNAP PAC Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
What You Will Need. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Installing Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Installing Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Installing Modules on the Rack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Removing a Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Installing the Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
What’s Next? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Chapter 3: System Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Communication Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Simultaneous Communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Accessing SNAP PAC Brains Over the Internet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Choosing Communication Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
System Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
SNAP PAC Brains as Part of a Distributed SNAP PAC System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
SNAP PAC Brain as an Independent I/O Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
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Networking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Connecting the Brain Directly to a PC or Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Attaching the Brain to an Existing Ethernet Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Using the Brain in an Independent Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Using SNAP PAC Brain Network Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Correct Connections for Daisy-Chaining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Incorrect Network Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
LEDs and Network Interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
SNAP PAC Brain Comparison Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Feature Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Chapter 4: Maintenance and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Maintaining the SNAP PAC Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Backup Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Changing the Brain’s IP Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Resetting the Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Loading New Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Setting Time and Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Blink Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Troubleshooting the SNAP PAC Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Getting Device and Firmware Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Communicating with the Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Pinging the Brain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Accessing the Brain with PAC Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Solving Network Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Additional Troubleshooting Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Making Sure the Brain is in Normal Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
TCP Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
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Chapter 1
1: Introduction
About SNAP PAC Brains
SNAP PAC brains are powerful and versatile I/O and communications processors for your SNAP PAC
System™. Designed primarily to work in distributed systems controlled by a SNAP PAC S-series or
R-series controller, SNAP PAC brains provide local intelligence that frees the controller for supervisory
tasks.
Two SNAP PAC brains are available: the SNAP-PAC-EB1 and the SNAP-PAC-EB2. They are identical
in their functions and features except that the SNAP-PAC-EB1 provides high-speed digital functions
and analog ramping. The SNAP-PAC-EB2 does not offer high-speed digital functions or analog
ramping. For a complete list of brain features, see page 18.
I/O Processing
As an I/O processor, the SNAP PAC brain provides the local intelligence to independently handle
functions such as latching, counting, thermocouple linearization, watchdog timers, and PID loop
control. These functions continue to work on the brain even if communication with the SNAP PAC
controller is lost.
Each SNAP PAC brain mounts on a SNAP PAC rack with up to 4, 8, 12, or 16 SNAP I/O™ modules.
Each module provides from 1 to 32 I/O points, depending on the module.
SNAP PAC brains support all the SNAP I/O analog, digital, serial, and special-purpose input and
output modules available on the Opto 22 website. These modules can all be mixed on the same
mounting rack and placed in any position on the rack, to accommodate the required mix of signals
at any location.
For more information on mounting racks, see Opto 22 form #1684, the SNAP PAC Racks Data Sheet.
For more information on I/O modules, visit our website at www.opto22.com.
Communications
In addition to I/O processing, SNAP PAC brains communicate over a standard 10/100 Mbps Ethernet
network. Each SNAP PAC brain is equipped with two switched Ethernet network interfaces. Because
these interfaces share a single IP address and act just like an Ethernet switch, SNAP PAC brains can be
SNAP PAC Brains User’s Guide 1
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ABOUT SNAP PAC BRAINS
installed in a multi-drop (daisy-chain) configuration, extending the control network without the
expense of additional Ethernet network hardware. SNAP PAC brains can also be installed in a star
configuration using standard, off-the-shelf Ethernet network components.
SNAP PAC brains support communication using multiple protocols running simultaneously over
Ethernet. Most customers use the PAC Project software suite for control, monitoring, and data
acquisition. At the same time, you can communicate using other methods.
PAC Project Software Suite
SNAP PAC brains are primarily designed for use with a SNAP PAC programmable automation
controller. The controller runs a control program, called a strategy, which you develop using PAC
Project™ software.
The PAC Project software suite comes in two forms, Basic and Professional:
• PAC Project Basic, which is included in the purchase of a SNAP PAC controller, consists of
• PAC Project Professional is available for purchase and adds OptoOPCServer™ for OPC
control programming, human-machine interface (HMI) creation, and configuration software.
communications, OptoDataLink™ for database connectivity, and additional features.
For more information about PAC Project, see form #1699, the PAC Project Data Sheet, available on our
website, www.opto22.com.
Other Communication Methods
In addition to using a SNAP PAC controller with PAC Project software, you can communicate with
SNAP PAC brains using Modbus®/TCP, SNMP for network management, FTP for the brain’s built-in file
system, SMTP (email client), and Opto 22’s own memory-mapped OptoMMP protocol.
Communication with OPC 2.0-compliant clients is available through OptoOPCServer.
• For Modbus/TCP, see Opto 22 form #1678, the Modbus/TCP Protocol Guide.
• For SNMP, FTP, and SMTP, see form #1704, the PAC Manager User’s Guide.
• If you are not using PAC Project but want to develop custom software to communicate with the
brain, the OptoMMP developer toolkit is available for free on our website, www.opto22.com.
The OptoMMP Communication Toolkit includes ActiveX components and C++ classes, so you
can use programming tools such as Visual Basic or Visual C++ to communicate with the brain.
See form #1465, the OptoMMP Protocol Guide, for more information.
• For OPC connectivity, use OptoOPCServer, available either as part of PAC Project Professional or
for separate purchase. See our website for more information.
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About this Guide
This guide shows you how to install and use SNAP PAC brains. This guide assumes that you have
some familiarity with TCP/IP and Ethernet networking. If you are not familiar with these subjects, we
strongly suggest you consult commercially available resources to learn about them before
attempting to install or use SNAP PAC brains.
The following sections are included in this user’s guide:
Chapter 1: Introduction—information about the guide and how to reach Opto 22 Product
Support.
Chapter 2: Installing a SNAP PAC Brain—quick-start steps to get SNAP PAC brains up and
running quickly.
Chapter 3: System Architecture—conceptual information on networking and communicating
with SNAP PAC brains, and brain specifications.
Chapter 4: Maintenance and Troubleshooting—changing IP addresses, resetting the brain to
factory defaults, and upgrading firmware; blink codes and other troubleshooting assistance.
CHAPTER 1: INTRODUCTION
Other Documents You May Need
See the following additional guides for the information listed. All guides are available on the Opto 22
website, www.opto22.com; some are included on the CD that came with the SNAP PAC brain.
For this information See this guide Form #
Assigning IP address, loading new firmware, etc. PAC Manager User’s Guide 1704
Designing flowchart-based control programs for
the system (requires a SNAP PAC S-series or
R-series industrial controller)
Communicating with SNAP PAC brains using OPC OptoOPCServer User’s Guide 1439
Connecting the SNAP PAC System with databases OptoDataLink User’s Guide 1705
Communicating with SNAP PAC brains using Modbus/TCP
Programming your own applications for SNAP PAC
brains using the OptoMMP Communication Toolkit
or the OptoMMP memory-mapped protocol
PAC Control User’s Guide 1700
PAC Control Command Reference 1701
PAC Control Commands Quick Reference Card 1703
Modbus/TCP Protocol Guide 1678
OptoMMP Protocol Guide 1465
SNAP PAC Brains User’s Guide 3
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FOR HELP
For Help
If you have problems installing or using SNAP PAC brains and cannot find the help you need in this
guide or on our website, contact Opto 22 Product Support.
Phone: 800-TEK-OPTO (835-6786)
951-695-3080
(Hours are Monday through Friday,
7 a.m. to 5 p.m. Pacific Time)
Fax: 951-695-3017
Email: support@opto22.com
Opto 22 website: www.opto22.com
When calling for technical support, be prepared to provide the following information about your
system to the Product Support engineer:
• Software and version being used
NOTE: Email messages and
phone calls to Opto 22
Product Support are
grouped together and
answered in the order
received.
• Brain and controller firmware version (as applicable)
• PC configuration (type of processor, speed, memory, and operating system)
• A complete description of your hardware and operating systems, including:
– loader and firmware versions for the brain, and date code (available through PAC Manager;
see page 26.)
– IP addresses and net masks for devices on the system
– type of power supply
– third-party devices installed (for example, barcode readers)
• Specific error messages seen
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SNAP PAC Brains User’s Guide
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Chapter 2
2: Installing a SNAP PAC Brain
If you already know how you will use the SNAP PAC brain and want to get it running quickly, follow
the sections in this chapter.
To learn about communication options and networking, start on page 9. Specifications are listed on
page 17.
What You Will Need
You’ll need the following items to install a SNAP PAC brain:
• PC running Microsoft® Windows® 2000 or higher, with a 10/100 MB Ethernet adapter card, the
TCP/IP protocol installed, and a valid IP address, on the same subnet as the brain. (For more
information, see “Networking” on page 13.)
• Standard Ethernet cable for direct connection to the PC, or an available connection to a
standard 10BASE-T or 100BASE-TX Ethernet network.
• SNAP PAC brain (See page 18 for a chart comparing models.)
• SNAP PAC mounting rack and SNAP I/O modules chosen for your application.
• A SNAP-PS5 or SNAP-PS5U power supply or other 5 VDC power supply (-0/+0.1 VDC at 4.0 A)
applied to the rack. (Additional power may be required for SNAP I/O modules depending on
the number and type of modules used. See the module data sheets on our website,
www.opto22.com, for information.)
Installing Software
In your CD-ROM drive, insert the CD that came with the brain. The installation wizard should start
automatically. If it doesn’t, use Windows Explorer to navigate to your CD-ROM drive and then
double-click setup.exe. Follow directions to install the software.
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INSTALLING HARDWARE
Installing Hardware
Assemble the rack and power supply according to the directions that came with them.
Installing Modules on the Rack
Modules snap into place in the row of connectors on the rack. Each module connector has a number.
NOTE: Any type of module can be placed in any position on the rack. Check module data sheets for power
requirements and any quantity limitations.
1. Place the rack so that the module connector numbers are right-side up, with zero on the left.
Brain connector
2. Position the module over the module connector, aligning the small slot at the base of the
Module
position zero
Module connectors
Retention bar
module with the retention bar on the rack.
3. With the module correctly aligned
over the connector, push on the
module to snap it into place.
When positioning modules next to
each other, be sure to align the male
and female module keys (shown in
the detailed view in the illustration at
right) before snapping a module into
position.
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SNAP PAC Brains User’s Guide
Modules snap securely into place and
require a special tool (provided) for
removal. To remove a module, see
page 7.
Page 11
4. (Optional) As shown in the photo at right,
use standard 4-40 x 1/2 truss-head Phillips
hold-down screws to secure both sides of
each module.
CAUTION: Do not over-tighten screws.
5. Plug the wiring connector into each
module to attach modules to the devices
they monitor.
Wiring diagrams are in the module’s data
sheet.
CHAPTER 2: INSTALLING A SNAP PAC BRAIN
Removing a Module
1. If the modules are held in place with
screws, remove them.
2. Holding the SNAP module tool
(provided) as shown in the illustration at
right, insert it into the notch at the base
of the module.
3. Squeeze the module tool against the
module to open the release latch, and
pull straight up on the module to
remove it.
4. Continue with “Installing the Brain” on
page 8.
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WHAT’S NEXT?
Installing the Brain
1. Remove the brain from its packaging.
2. Turn off power to the rack assembly.
3. Align the brain connector with the mating
connector on the mounting rack.
4. Seat the brain onto the connector and use
the hold-down screw to secure the brain in
position. Do not overtighten.
5. Using Category 5 or superior solid
unshielded twisted-pair cable, connect the
brain in one of the following ways:
– (Recommended for initial configuration)
Connect to a PC directly, using a
standard Ethernet cable.
– Connect to a standard 10BASE-T or 100BASE-TX Ethernet network that has a PC on the
same subnet as the brain and does NOT have a Dynamic Host Configuration Protocol
(DHCP) server.
6. Before turning on power to the rack, follow instructions in Opto 22 form #1704, the PA C
What’s Next?
To start configuring I/O points, see instructions the PAC Control User’s Guide, form #1700. (If you are
not using PAC Control, follow configuration steps in the PAC Manager User’s Guide.)
To learn more about SNAP PAC brain capabilities and network options, see Chapter 3: System
Architecture. If you are planning to install multiple brains in a daisy-chain configuration, see “Using
SNAP PAC Brain Network Interfaces” on page 15.
To use OLE for process control (OPC) with SNAP PAC brains, purchase the OptoOPCServer and see
Opto 22 form #1439, the OptoOPCServer User’s Guide.
To communicate with SNAP PAC brains using Modbus/TCP, see form #1678, the Modbus/TCP Protocol
Guide.
To program your own applications to communicate with the SNAP PAC brain, see Opto 22 form
#1465, the OptoMMP Protocol Guide.
Maximum cable or segment length is 100 meters; minimum cable length is one meter.
Manager User’s Guide, to assign an IP address to the brain.
This guide is in Adobe Acrobat PDF format on the CD that came with the brain and is also
available from our website, www.opto22.com.
8
SNAP PAC Brains User’s Guide
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Chapter 3
3: System Architecture
This chapter explains how to use SNAP PAC brains in an Ethernet network and how to communicate
with them. It includes information on:
Communication options See below
System architecture See page 12
Networking See page 13
Specifications and feature comparison charts See page 17
Communication Options
SNAP PAC brains communicate using TCP/IP or UDP/IP over a wired or wireless network.
Physical Layer—SNAP PAC brains communicate over a 10- or 100-Mbps wired Ethernet link.
Transport Layer—The key to the SNAP PAC brain‘s communication flexibility is the transport layer,
Internet Protocol (IP). Both the Transmission Control Protocol (TCP) and the User Datagram Protocol
(UDP) are used with IP.
Application Layer—Because SNAP PAC brains use standard IP for the transport layer, many
communication options are possible in the application layer. After the I/O unit is installed and has an
IP address assigned (see page 8), you can communicate with it using the following methods:
• PAC Control strategies running on a SNAP PAC controller can configure, read, and write to I/O
points on SNAP PAC brains.
• PAC Manager software, in addition to its use for assigning IP addresses, can also be used to
configure I/O points and features, and perform onetime reads and writes.
• Modbus/TCP provides a direct connection with Modbus/TCP hardware or software or
third-party software applications, which can read or write to I/O points on SNAP PAC brains.
•OPC (OLE for Process Control) uses OptoOPCServer to serve data to any OPC 2.0-compliant
application, such as an HMI, which can also read or write to I/O points. OptoOPCServer can be
purchased separately or as part of the PAC Project Professional software suite.
SNAP PAC Brains User’s Guide 9
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COMMUNICATION OPTIONS
• OptoDataLink exchanges I/O point data with ODBC-compliant databases, including Microsoft
• SMTP (Simple Mail Transfer Protocol) connects a SNAP PAC brain with corporate email servers,
•SNMP (Simple Network Management Protocol) makes it possible to monitor devices attached
•FTP (File Transfer Protocol) can be used to transfer files and data to and from the SNAP PAC
• Custom software applications are easy to develop using our OptoMMP Communication
SQL Server, Microsoft Access, MySQL, and others. OptoDataLink can be purchased separately or
as part of PAC Project Professional.
so employees can be emailed or paged if there’s a problem on devices attached to the brain.
to SNAP PAC brains just as you would any computer or server on the Ethernet network, using an
SNMP-based enterprise management system such as Computer Associates’ Unicenter®,
Hewlett-Packard’s OpenView®, or IBM’s Tivoli®. When a monitored event occurs, such as a door
left open or a pressure level too high, the brain sends an SNMP trap to the management
system.
brain, whether to custom applications, enterprise databases, or any file system.
Toolkit with ActiveX components and C++ classes. They use the OptoMMP protocol, an IEEE
1394-based protocol, to read and write to SNAP PAC brains. For developers not using Microsoft
Windows, our OptoMMP protocol is open and documented.
Simultaneous Communication
In addition to communicating using all the methods listed above, each SNAP PAC brain can also
communicate simultaneously using all of these methods.
The reason lies in the nature of IP. In serial communication, a single data request is sent by one device
to another. The first device must wait for a response before any additional communication can be
carried out. IP, however, can establish multiple simultaneous sessions, so many data requests can be
sent at once without waiting for any individual response. Each request gets a response, but the link
isn’t idle while waiting for responses.
In addition, IP can simultaneously handle multiple requests from multiple devices. A PC can
communicate with all SNAP PAC brains and controllers on the same network—all at the same
time—and multiple PCs can communicate with one SNAP PAC device at the same time.
So, for example, a SNAP PAC brain can respond to directions from a Modbus master, give analog
point data to a technician using PAC Manager, and carry out instructions from a custom C++
application—all at once.
Accessing SNAP PAC Brains Over the Internet
Since SNAP PAC brains are just like any other hardware on the Ethernet network, you can access
them over the Internet in exactly the same way you would access a computer. The details depend on
your network and Internet connection. Consult your system or network administrator or your
Internet Service Provider (ISP) for more information.
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CHAPTER 3: SYSTEM ARCHITECTURE
Choosing Communication Methods
How do you need to communicate with SNAP PAC brains to match the tasks your application
requires? Check the following table for help in choosing communication methods and finding out
where to look for more information on them.
This task Can be done using these methods Comments and references
Recommended Alternate
Configure I/O units.
Monitor and control processes; acquire data.
Give technicians an Opto 22
HMI with alarming and trending.
Communicate with Modbus/TCP hardware or software.
Exchange I/O point data with
third-party software such as
HMIs and databases.
Send email or page someone.
Send SNMP trap.
Monitor devices through an
enterprise management system.
PAC Control (I/O
points only) or PAC
Manager (I/O points
and other functions)
PAC Control flowchart logic
PAC Display See PAC Display User’s Guide.
Modbus/TCP See Modbus/TCP Protocol Guide.
OptoOPCServer for
OPC; OptoDataLink
for databases
PAC Control (and
PAC Manager for
configuration)
OptoMMP Communication Toolkit or
OptoMMP protocol
PAC Manager
Inspect window or
OptoMMP Communication Toolkit or
OptoMMP protocol
OptoMMP Communication Toolkit or
OptoMMP protocol
If you are using PAC Control, configure the system in
PAC Control. See the PAC Control User’s Guide.
For the Communication Toolkit or OptoMMP protocol,
see OptoMMP Protocol Guide.
See PAC Control User’s Guide & Command Reference.
CAUTION! Events and reactions set up using alternate
methods are faster than flowchart logic, but be careful if
you use them. They can conflict with PAC Control logic,
because both write to the brain’s memory map. For Communication Toolkit or OptoMMP protocol, see OptoMMP
Protocol Guide.
Purchase OptoOPCServer or OptoDataLink separately
or as part of PAC Project Professional. See OptoOPC-
Server User’s Guide and OptoDataLink User’s Guide.
If you are using PAC Control, configure email using PAC
Manager. See the PAC Manager User’s Guide.
For Communication Toolkit or OptoMMP, see OptoMMP
Protocol Guide.
Write your own software
application to communicate
with the system.
C++ or Active X:
OptoMMP Communication Toolkit and
brain’s memory map.
Opto 22’s OptoMMP
protocol and brain’s
memory map.
See OptoMMP Protocol Guide.
SNAP PAC Brains User’s Guide 11
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SYSTEM ARCHITECTURE
System Architecture
SNAP PAC brains can be used in two ways:
• For distributed intelligence in a larger control system based on a SNAP PAC controller running
PAC Control
• As an independent I/O processor
The following diagrams illustrate these two uses.
SNAP PAC Brains as Part of a Distributed SNAP PAC System
The following diagram shows only basic SNAP PAC System capabilities using free PAC Project Basic
software. For information on additional capabilities, such as communication with OPC clients,
databases, and third-party systems, see form #1696, the SNAP PAC System Data Book.
PC used to develop
PAC Control strategy
Distributed SNAP PAC brains and I/O
PC used for PAC Display HMI
SNAP PAC S-series controller
running PAC Control strategy
Ethernet network
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CHAPTER 3: SYSTEM ARCHITECTURE
SNAP PAC Brain as an Independent I/O Processor
As the following diagram illustrates, you can communicate with an independent SNAP PAC brain
using Modbus/TCP, the OptoOPCServer (available separately), SNMP, SMTP, or applications you
develop using the free OptoMMP Communication Toolkit or our OptoMMP protocol.
Custom application using
OptoMMP protocol
Modbus/TCP
Ethernet network
ActiveX or C++
Any OPC client software,
through OptoOPCServer
(purchase separately)
Third-party HMI
•Wonderware
• Intellution
•Iconics
Networking
Modbus/TCP hardware
and software
From a physical standpoint, SNAP PAC brains can be networked in several ways:
• Connected directly to a PC or controller using a standard Ethernet cable
• Attached to an existing TCP/IP Ethernet network
• As part of an independent network built with standard Ethernet hardware
The networking method you use depends on several things, including whether you need control or
data acquisition, the number of PCs and I/O units you are using, the speed and volume of
communication, security requirements, and the availability of an Ethernet network.
As an option in any network, you can install multiple brains in a daisy-chain configuration. See
page 15 for more information.
SNAP PAC Brains User’s Guide 13
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NETWORKING
Connecting the Brain Directly to a PC or Controller
A direct connection using a standard Ethernet cable connects the SNAP PAC brain with one host,
either a PC or a controller. (A crossover cable is not required for direct connection to a host.) You can
use either Ethernet interface on the brain for the connection. Additional SNAP PAC brains can be
daisy-chained from the first brain using the brain’s second Ethernet network interface, which acts as
a network switch. See “Using SNAP PAC Brain Network Interfaces” on page 15 for more information.
If you need only a small control or monitoring network and have no existing Ethernet network, a
direct connection is ideal. It’s quick, easy, and inexpensive because it requires only cables (no
separate Ethernet switches or routers). It also provides high speed and high security for a small
system.
A direct connection is also useful for assigning an IP address, configuring I/O points, and testing
applications. The direct connection eliminates other variables that could interfere with
communication, so you can focus on maintenance and troubleshooting.
Attaching the Brain to an Existing Ethernet Network
The first rule in attaching SNAP PAC brains to an existing network is to work closely with your system
administrator, who must determine network topology and hardware. Be sure to consider the impact
on your existing network of adding the brains. For best performance, use a 100 Mbps network.
In addition, make sure the system administrator understands that each brain must have a fixed
(static) IP address, whether or not a Dynamic Host Configuration Protocol (DHCP) server is used on
the network. For more information on IP addresses, see the PAC Manager User’s Guide.
Because the SNAP PAC brain has two switched Ethernet interfaces, the brains can optionally be
daisy-chained together. (See “Using SNAP PAC Brain Network Interfaces” on page 15.)
If you need to isolate the control system data from the main network backbone, you can use a router,
network switch, or other gateway device. You can also use a SNAP PAC controller, which has two
independent Ethernet network interfaces: one interface can be connected to the enterprise network,
and the other used for the control system. See Opto 22 form #1696, the SNAP PAC System Data Book,
for more information on network options.
Using the Brain in an Independent Network
The third way SNAP PAC brains can be used is by developing an independent network. An
independent network gives a high level of communication speed and volume, as well as high
security. You may also need a separate network for critical control applications. Again, the choice
depends on your requirements for data transactions, data security, and whether a near-deterministic
system is necessary.
If you are building your own network, remember that each brain must have a fixed IP address. See
the PAC Manager User’s Guide for more information on IP addresses.
14
If you have no existing Ethernet network, you can use off-the-shelf Ethernet components to build
one. Since Ethernet and TCP/IP are worldwide standards, there are a number of commercially
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CHAPTER 3: SYSTEM ARCHITECTURE
available resources for learning about building and maintaining such a network. We strongly
suggest you learn as much as possible about the subject and plan your network carefully before
beginning, in order to get the best performance from your system.
Because SNAP PAC brains have two switched Ethernet network interfaces, you can install them in a
daisy-chain configuration. See the next section for more information.
Using SNAP PAC Brain Network Interfaces
As illustrated conceptually at right, SNAP PAC brains
Ethernet 1
Ethernet 2
have two Ethernet network interfaces. Ethernet 1 and
Ethernet 2 are not redundant interfaces; they are
Unmanaged switch
connected by an unmanaged switch.
Unmanaged switch
Ethernet devices are normally networked in a standard
star configuration. If you are using this standard
configuration, connect either Ethernet 1 or Ethernet 2 to
Brain
the network. The two interfaces share the same IP
address, and either one will send a BootP request.
As an option, however, the SNAP PAC brain’s two
switched Ethernet interfaces let you use a daisy-chain
configuration for distributed I/O, connecting just one
brain to the network and then connecting subsequent
brains in a chain.
The primary advantage of daisy-chaining is that you save the expense of network routers or switches.
The primary disadvantage is similar to that of a serial network: if communication with one brain is lost,
communication to all brains beyond it on the daisy chain will also be lost.
IMPORTANT: If you choose a daisy-chain configuration, make certain that the brains are connected
correctly. Incorrect connections can produce major problems on the network. Make sure that daisy-chain
connections are made in a simple open-ended chain, as shown in the diagram on the following page.
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NETWORKING
Correct Connections for Daisy-Chaining
Connection from network,
controller, or PC to brain
Daisy-chain connections
NOTE: Connection
from a PC does not
require a crossover
cable.
Leave the 2nd
interface on the last
brain unconnected.
Never connect SNAP PAC brains in a loop or ring. For example, do not connect both ends of the
chain to the same switch, nor to different switches on the same network. As a rule, do not connect
the second Ethernet interface on the last brain in the chain to any other device.
NOTE: There is one exception to this rule: you can connect the network in a loop if at least one switch in the
loop supports STP/RSTP (Spanning Tree Protocol/Rapid Spanning Tree Protocol) and has that feature
enabled.
Incorrect Network Connections
Ethernet switch
Ethernet switch
Ethernet switch
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SNAP PAC Brains User’s Guide
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Specifications
Specifications
Power Requirements 5.0–5.2 VDC at 750 mA maximum (does not include module power requirements)
Memory 16 MB RAM
Backup battery CR2032 Lithium, user replaceable. 10-year minimum life for real-time clock backup.
CHAPTER 3: SYSTEM ARCHITECTURE
Network Interfaces
Maximum Ethernet
Segment Length
Operating Temperature
Storage Temperature -40 to 85 °C
Humidity 0–95% humidity, non-condensing
IEEE 802.3 network, 10Base-T and 100Base-TX. Automatic MDC/MDI-X crossover
(Ethernet crossover cable not required for direct connection to PC). Two switched
ports, allowing multi-drop (daisy-chain) or standard star network configuration.
100 meters with Category 5 or superior UTP.
For 100 Mbps at this distance, use Category 5 or superior solid UTP.
0 to 60 °C
LEDs and Network Interfaces
Switched Ethernet network interfaces
Brains can be networked in a daisy-chain
configuration or in a standard star
configuration using either Ethernet interface.
Both interfaces use the same IP address.
NOTE: When using a daisy-chain
configuration, be aware that if power to a
brain is lost, all brains beyond it on the
network will also lose communication.
Akso see
LEDs
LED Indicates
LNK
ACT
STAT Brain status
MS
NS
Unnamed
Link established with
Ethernet network
Activity on Ethernet
network
Reserved for future
use
SNAP PAC Brains User’s Guide 17
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SNAP PAC BRAIN COMPARISON CHART
SNAP PAC Brain Comparison Chart
For descriptions of features, see page 19. The following table compares SNAP PAC brains with
firmware 8.0.
FEATURE SNAP-PAC-EB1 SNAP-PAC-EB2
I/O modules
supported
Digital I/O point
features
Digital (4–32 channels)
Analog (2–32 channels) nn
Serial (RS-232, RS-485) nn
Special-purpose (motion control, power monitoring, Profibus
On/off status
Input latching nn
Watchdog timer
High-speed counting (up to 20 kHz)
Quadrature counting
On-pulse and off-pulse measurement
TPO (time-proportional output)
Pulse generation (N pulses, continuous square
wave, on-pulse, and off-pulse)
Thermocouple linearization (32-bit floating
point for linearized values)
Minimum/maximum values nn
Offset and gain nn
®
, Wiegand®)
1
2
1
1,3
3
3
nn
nn
nn
nn
n
n
n
n
n
nn
18
Analog I/O point
features
Ethernet networking nn
Two switched Ethernet network interfaces (one IP address) nn
Maximum number of modules allowed per I/O unit (with largest rack):
Any mix of 16 digital, 16 analog, 8 serial or special-purpose
PID logic on the brain (96 PID loops per brain) nn
Modbus®/TCP nn
OPC driver support nn
OptoMMP memory-mapped protocol nn
SNAP PAC Brains User’s Guide
Scaling nn
Time-proportional output
Output clamping nn
Filter weight nn
Watchdog timer nn
Ramping
3
4
nn
n
nn
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CHAPTER 3: SYSTEM ARCHITECTURE
FEATURE SNAP-PAC-EB1 SNAP-PAC-EB2
SNMP
(network management)
FTP server, file system nn
Email (SMTP client) nn
5
nn
Scratch Pad area for peer-to-peer data
(bits, floats, integers, and strings)
Digital events1, Alarm events, Serial events, and Timed events
Event messaging nn
UDP Streaming nn
Data logging in the brain nn
Security (IP filtering, port access) nn
Realtime clock (RTC) nn
I/O point data mirroring and memory map copying nn
1 Four-channel digital modules only; not available on high-density digital modules.
2 Requires a SNAP quadrature input module (SNAP-IDC5Q).
3 Available when used with PAC Control Professional and a SNAP PAC controller.
4 Requires a SNAP analog TPO module (SNAP-AOD-29).
5 Currently not available on analog modules with more than 4 points.
1
nn
nn
Feature Descriptions
See the feature table on page 18. For additional information, including configuration, see the PAC
Manager User’s Guide.
Feature Description
States
Latches
Counters
Quadrature
counters
(Digital input and output)—A digital point is either on or off. You can read the current
state of a digital input or write an on/off state to a digital output.
(Digital input)—When the value of a digital input point changes from off to on, an
on-latch is automatically set. While the value of the point may return to off, the on-latch
remains set, as a record of the change, until you clear it. Similarly, an off-latch is set
when the value of a digital point changes from on to off, and it remains set until cleared.
(Digital input)—A counter keeps track of the number of times a digital input changes
from off to on. The count accumulates until it reaches the maximum count available in
the brain or until you reset the counter to zero. For example, to count the number of widgets produced per shift, you would clear the counter at the start of each shift and read it
at the end of each shift.
SNAP-PAC-EB1 brains offer high-speed counting (up to 20 KHz) on 4-channel modules;
the speed of the counter depends upon the speed of the module used.
Both brains offer low-speed counting (about 50 Hz) on high-density modules; counting
is done in the module.
(Digital input)—A quadrature counter requires a SNAP quadrature input module, which
is attached to the encoder device. The module sends a pulse to the brain upon each
change in quadrature state, and the brain counts the pulses and keeps track of the
direction and rotation.
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SNAP PAC BRAIN COMPARISON CHART
Feature Description
Time-proportional
output (TPO)
Time-proportional output varies the duty cycle and the percentage of on time within that
cycle. TPO is often combined with a PID loop and used to control the output, for example in a heater or oven.
(Digital output)—Supported by SNAP-PAC-EB1 only; requires PAC Project Pro and a
SNAP PAC controller.
(Analog output)—Both SNAP PAC brains support analog TPO using a SNAP-AOD-29
module.
On-pulse and
off-pulse measure-
ment
Pulse and square
wave generation
Watchdog
Scaling
Minimum and
maximum values
Thermocouple linearization
(Digital input; requires SNAP-PAC-EB1, PAC Project Pro, and a SNAP PAC controller)—A pulse is a brief on (or off) state, usually repeated at a specific interval. The brain
can measure the first pulse, that is, the amount of time the input stays on (or stays off).
(Digital output; requires SNAP-PAC-EB1, PAC Project Pro and a SNAP PAC controller)—A pulse turns a digital output on (or off) briefly, either once or for a specified number of times at a specified interval. A digital square wave is a specific pattern of on and
off states, repeated continuously.
(Digital and analog input and output)—A watchdog monitors communication with the PC
or other host device. If the host does not write data to the I/O unit for the length of time
set in the watchdog, the I/O unit automatically sets designated digital and analog output
points to the values you have determined.
If communication fails between the host and the brain controlling a process, a watchdog
makes sure the process is automatically brought to a safe state. For example, a valve
could automatically close to avoid completely emptying a tank.
(Analog input and output)—Analog input and output points can be scaled as needed.
For example, you can scale a -5 V to +5 V input point to reflect 0% to 100%
(Analog input)—Minimum and maximum values are sometimes called peaks and valleys. You can read these values at any time, for example, to record minimum and maximum temperatures. You can also reset min/max values. For example, if you want to
record the maximum temperature at point 2 in each 24-hour period, you must reset the
values after they are read each day.
(Analog input)—The brain automatically converts the thermocouple junction's millivolt
values into temperature values, so you don’t have to. Choose the appropriate module
and make sure you configure the point as the correct thermocouple type (E, K, etc.) for
your purpose.
20
Offset and gain
Clamping
Ramping
PID loop control
Average filter
weight
SNAP PAC Brains User’s Guide
(Analog input)—Offset and gain calculations are used to calibrate analog points. If a -50
mV to +50 mV input receives signals that are slightly off (not exactly -50 mV at the lowest point, for example), the offset and gain can be calculated so that values will appear
accurately when read.
(Analog output)—Clamping limits values that can be sent to analog output points so
they do not go above or below a specific value. For example, if you are using a 0–10
VDC output module, but the device attached to one of its points can only handle a maximum of 5 VDC, you can set an upper clamp of 5 VDC for that point. The values for
upper and lower clamp are set in engineering units.
(Analog output; requires SNAP-PAC-EB1, PAC Project Pro, and a SNAP PAC controller)—Some devices attached to analog outputs should not be abruptly stepped up or
down, because a sudden change might damage the equipment or cause other problems. Instead, you can gradually ramp the device up or down to the desired value.
(Analog points)—Proportional integral derivative (PID) loops are used to drive an input
toward a particular value (the setpoint) and keep the input very close to that value by
controlling an output. PID loops are often used in temperature control.
(Analog inputs)—A filter weight smooths analog input signals that are erratic or change
suddenly. See the PAC Manager User’s Guide for more details.
Page 25
Feature Description
You can configure a SNAP PAC brain to recognize one or a combination of the following
as an event:
• The state of a point on a 4-channel digital module (on or off)
• A specific high or low value of an analog point, in Engineering Units
• A number on a digital counter or a high or low number on a quadrature counter
Events, Timers,
Event Messages,
Email, Data Log-
ging, Data Mirror-
ing, and Memory
Map Copying
Security
• An analog point value or a quadrature counter that is outside an allowable range
• The state of a bit in the Scratch Pad (on or off)
• A specific string received by a serial module.
The brain can react automatically to an event in any or all of the following ways:
• Turning points on 4-channel digital modules on or off (same or different brain)
• Copying data from one memory map location to another (same or different brain)
• Logging data
• Turning a bit in the Scratch Pad on or off
• Sending a stream packet, an email message, or an SMNP trap
• Sending a string through a serial module to a serial device
You can also use a timer to set up a delay between the event and the reaction.
You can limit access to SNAP PAC brains either by allowing access only from specific
computers or other devices on the network (IP filtering), or by limiting access to specific
protocols, such as SNMP, that are used with the brain (port access).
CHAPTER 3: SYSTEM ARCHITECTURE
Scratch Pad Areas
SNMP
FTP Server
The Scratch Pad is used primarily for peer-to-peer communication with other SNAP PAC
brains and controllers on the network. See the PAC Control User’s Guide.
The Simple Network Management Protocol (SNMP) is used to communicate with an
SNMP-based enterprise management system, such as Computer Associates’
Unicenter, Hewlett-Packard’s OpenView, or IBM’s Tivoli. These systems can manage
analog, digital, or serial devices through a SNAP PAC brain just as they manage computer equipment on the Ethernet network.
SNAP PAC brains have a substantial area available for file storage, and data can be
easily moved to and from these files using FTP. For more information on the file system,
see the PAC Manager User’s Guide.
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SNAP PAC BRAIN COMPARISON CHART
22
SNAP PAC Brains User’s Guide
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Chapter 4
4: Maintenance and Troubleshooting
Introduction
This chapter includes the following maintenance and troubleshooting information:
Maintenance
Backup Battery
Changing the Brain’s IP Address
Resetting the Brain
Loading New Firmware
Setting Time and Date
Blink Codes
Troubleshooting
Getting Device and Firmware Information
Communicating with the Brain
Additional Troubleshooting Tools
Maintaining the SNAP PAC Brain
Backup Battery
below
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page 25
page 25
page 26
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page 30
The real-time clock on the SNAP PAC brain uses a CR2032 lithium backup battery, which is user
replaceable. These batteries are readily available in retail stores.
SNAP PAC Brains User’s Guide 23
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MAINTAINING THE SNAP PAC BRAIN
Changing the Brain’s IP Address
If you know the SNAP PAC brain’s IP address, see the PAC Manager User’s Guide for instructions to
change it.
If you do not know the IP address, first check the label on the side of the brain. If you still don’t know
the brain’s IP address, follow the steps in the next section to restore the brain to factory default
settings, and then assign an IP address as described in the PAC Manager User’s Guide.
Resetting the Brain
1. Carefully insert a straightened paperclip or stiff wire into the small hole labeled RESET.
2. Press and hold down the RESET button as described below.
To perform this kind of reset... ...do this Result
Simple restart
Restore factory default
settings
Press and hold the RESET button
for less than 1 sec. until the STAT
LED turns off, and then immediately release the button.
OR
Turn off power to the brain and
then turn it on again.
OR
Use PAC Manager to send the
brain the “Restart from Powerup”
command.
Press and hold the RESET button
for 1 or 2 seconds until the STAT
LED turns solid green, and then
immediately release the button.
• The brain restarts.
• Any files in RAM are erased. If files
have been stored to flash memory,
they will not be erased.
• The brain restarts.
• Files in RAM and flash memory
are erased.
• IP address is reset to 0.0.0.0 and
subnet mask to 255.255.255.0.
CAUTION: If you hold down the RESET button longer than the time needed to restore the default settings,
the brain will restart in fail-safe bootloader mode, which is indicated by the STAT LED blinking green 7
times quickly. This is a diagnostic mode that you don’t need to access unless you are troubleshooting a
problem with Opto 22 Product Support. If your brain restarts in fail-safe bootloader mode, simply cycle
power to the device. This action performs the simple restart described above.
24
Loading New Firmware
Each SNAP PAC brain contains firmware (sometimes referred to as the kernel), which is similar to an
operating system. If the firmware should become damaged, or if a new version of the firmware is
released, you can load new firmware to the brain following instructions in the PAC Manager User’s
Guide.
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CHAPTER 4: MAINTENANCE AND TROUBLESHOOTING
Setting Time and Date
The SNAP PAC brain’s built-in clock is set at the factory. To change the time and date, see instructions
in the PAC Manager User’s Guide.
Blink Codes
The STAT LED on the top of a SNAP PAC brain uses blink codes to indicate status conditions. (See
“LEDs and Network Interfaces” on page 17 for the location of the STAT LED.) The blink codes can be
useful during operation and in troubleshooting.
If the STAT LED is on and remains green, the brain has an IP address and is operating normally.
If the STAT LED blinks orange about four times a second, the device is attempting to obtain an IP
address by sending BootP requests.
If the STAT LED blinks green when the brain starts up, it indicates the following:
Number of
Blinks
2 fast Normal; the brain’s firmware is starting up.
5 fast Default settings have been successfully restored.
7fast
Speed of
Blinks
Means
Entering fail-safe bootloader mode. (See “Resetting the
Brain” on page 24 for more information.)
If the STAT LED is blinking red, it indicates the following:
Number of
Blinks
4slow
5 slow Fatal error
6 slow RAM error Contact Product Support.
7 slow Ethernet switch failure Contact Product Support.
11 slow
Speed of
Blinks
Means Problem and Workaround
Invalid MAC address or
hardware revision
Ethernet loopback test failure
Contact Product Support.
Firmware or hardware problem. Check the power
supply and connections before restarting. Call Product Support if the error is repeated.
Make sure an Ethernet cable is connecting the two
network interfaces. If the error is repeated, contact
Product Support.
13 slow Real-time clock failure Contact Product Support.
16 slow Serial flash failure Contact Product Support.
20 slow Digital failure Contact Product Support.
21 slow Bus failure Contact Product Support.
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Troubleshooting the SNAP PAC Brain
If you encounter a problem while installing or using the SNAP PAC brain, check the information in
this section. If you need to contact Opto 22 Product Support, see “For Help” on page 4.
Getting Device and Firmware Information
If you need to contact Opto 22 Product Support for assistance, it is helpful to have device and
firmware information at hand before you call us.
1. Choose Start➞Programs➞Opto 22➞PAC Project Software➞PAC Manager.
2. In the PAC Manager main window, click the Inspect button .
3. In the IP Address field, type the IP address of the device. Click Status Read.
26
Keep this window open on your screen when you call Product Support.
Communicating with the Brain
If you attempt to connect to the brain using its IP address and you cannot, first check the following:
• Make sure the brain has been turned on and the LNK and STAT LEDs for the connected Ethernet
interfaces are lit (see “LEDs and Network Interfaces” on page 17.)
• If the brain has been networked in a daisy-chain configuration, check to see if another brain in
the chain has lost power. Also make sure all network connections are correct. (See “Using SNAP
PAC Brain Network Interfaces” on page 15.)
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• Make sure the brain’s hold-down screw has been tightened so that it is firmly attached to the
rack. (Do not overtighten.)
• Verify that you typed in the correct address for the brain. Check the label on the side of the
brain, where the IP address should be written.
• Make sure the brain has been assigned a valid IP address and subnet mask. SNAP PAC brains
come from the factory with a default IP address of 0.0.0.0, which is invalid. The default subnet
mask is 255.255.255.0. To assign an IP address and subnet mask, see the PAC Manager User’s
Guide.
• Make sure that no red LEDs on the brain are lit. A red LED could indicate a voltage supply
problem. Each brain should have its own power supply. The brain needs a minimum of 5.0 VDC,
measured at the rack.
• Make sure you have up-to-date drivers installed on your computer’s Network Interface Card
(NIC). Contact your system administrator or the manufacturer of the card for help.
• Make sure you have Administrator privileges on your computer and that any firewall in the
computer (such as the built-in firewall in Windows XP) is temporarily disabled before you try to
assign or change IP addresses, load firmware using PAC Manager’s Maintenance window, or
work with files on the brain. BootP and FTP cannot function through a firewall in the PC.
Firewalls in a router are less likely to be a problem.
Pinging the Brain
If you still cannot communicate with the brain after you have checked these items, try to reach it
using the PING protocol.
1. Choose Start➞Programs➞Accessories and open a command prompt window.
2. At the prompt, type: ping [brain’s IP address]
For example, type: ping 10.192.54.40
If the brain responds, go to “Accessing the Brain with PAC Manager” on page 28.
If the PING command cannot be found, choose Start➞Control Panel➞Network. Make sure
TCP/IP is configured as a protocol and that an IP address and subnet mask are assigned.
If you see the message “Destination host route not defined,” the brain probably has an
inappropriate IP address and subnet mask. Make sure the IP address and subnet mask on the brain
are compatible with those on the computer. Follow the directions beginning on page 24 to check
the IP address and subnet mask on the brain, and change them if necessary.
If you see the message “No response from host,” check the following:
• Are the computer and brain correctly connected? Is the brain turned on?
• Are the IP address and subnet mask on the brain compatible with those on the computer?
• Is the brain in reset mode? (Check for a blinking STAT LED. STAT blink codes are shown on
page 25.)
If you still cannot ping the brain, contact Opto 22 Product Support. (See page 4.)
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Accessing the Brain with PAC Manager
Once you know you can ping the brain, try to access it using PAC Manager. You will need to know
the brain’s IP address.
1. If PAC Manager is not already open, choose Start➞Programs➞Opto 22➞ PAC Project➞PA C
Manager.
The PAC Manager main window opens:
2. In the PAC Manager main window, click the Inspect button .
3. In the IP Address field, type the IP address of the brain (or choose it from the drop-down list).
Click Status Read.
Information from the brain is displayed in the window:
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If information does not appear, contact Product Support. (See page 4.)
Date and
time data
was last
read
Click to
update
data
Solving Network Problems
If there are recurring problems in communicating with the brain, check your network. The cables,
routers, and so on in your Ethernet network are not part of the Opto 22 hardware, but any problems
in your network may affect communication with Opto 22 products.
Create a Network Diagram—First, create a network diagram and verify the following:
• Cable connectors are firmly inserted.
• The Ethernet network switch has power. Switch LEDs indicate that the connection is up. If SNAP
PAC brains are daisy-chained, LNK LEDs for both of their Ethernet interfaces are lit.
• Neither the PC nor the brain uses the switch’s uplink port.
• The two switched network interfaces on the brain are being used correctly and are not creating
a loop anywhere in the network (see “Using SNAP PAC Brain Network Interfaces” on page 15).
• The brain’s LNK LED(s) are lit.
Check Ethernet Errors—Next, use PAC Manager to check Ethernet errors reported by the brain.
These errors indicate network problems. You will need to know the brain’s IP address.
1. Choose Start➞Programs➞Opto 22➞PAC Project Software➞PAC M a n ag e r.
2. In the PAC Manager main window, click the Inspect icon .
3. In the IP Address field, type the IP address of the brain. Click Status Read.
4. Scroll down until you see the items Ethernet Errors: Late Collisions, Ethernet Errors: Excessive
Collisions, and Ethernet Errors: Others.
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TROUBLESHOOTING THE SNAP PAC BRAIN
Ethernet Errors
All three of these items should have a value of zero. If any of these items has a value other than zero,
you may have a network problem.
Analyze Communication Packets—If it appears that you have network problems, you can use a
utility program such as WireShark (www.wireshark.org) to log and analyze network communication
packets.
Have Your Network Certified—If you suspect network problems, you may need to have your
network professionally certified. Opto 22 does not offer network validation or certification services,
but many network hardware manufacturers do. Contact the manufacturer of your Ethernet network
hardware to have them diagnose, fix, and certify your network.
If you continue to have problems communicating with the SNAP PAC brain after your network is
certified, contact Opto 22 Product Support. (See page 4.)
Additional Troubleshooting Tools
Making Sure the Brain is in Normal Mode
If you are having trouble communicating with the brain, it might be in fail-safe bootloader mode. This
is a diagnostic mode that you don’t need to access unless you are troubleshooting a problem with
Opto 22 Product Support. The brain restarts in fail-safe bootloader mode when you hold down the
RESET button longer than the time needed to restore the default settings. If your brain restarts in
fail-safe bootloader mode, simply cycle power to the device. This action performs a simple restart
and allows you to communicate with the brain. For more information on using the RESET button, see
“Resetting the Brain” on page 24.
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TCP Settings
Retransmit timeout (RTO) refers to the length of time the brain waits while communicating before
timing out. The RTO is determined by the brain’s TCP/IP stack, and the stack continually recalculates
the RTO based on recent network traffic. If the network becomes busier, for example, the stack
automatically adjusts the RTO to a higher value.
If the TCP/IP stack times out while trying to transmit data, it doubles the current RTO and tries again.
This process continues for five retries; after that, the brain stops trying and sends a timeout message.
If you are receiving frequent timeout messages from the brain, you can change the TCP parameters
in PAC Manager.
1. Choose Start➞Programs➞Opto 22➞PAC Project Software➞PAC Manager.
2. In the PAC Manager main window, click the Inspect icon .
3. In the IP Address field, type the IP address of the brain. Click Status Write.
CAUTION: Note the following recommended settings:
TCP Minimum Retransmission Timeout (msec): 250
TCP Initial Retransmission Timeout (msec): 3000
TCP Retransmission Attempts: 5
TCP Idle Session Timeout (msec): 240,000
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If you set these fields too low, you may not be able to communicate with the device at all, even
through PAC Manager, to fix the settings. Then you would have to reset the brain to factory defaults
(see page 24).
4. Change these four fields as necessary:
Minimum RTO sets an absolute minimum value for the RTO. The device’s calculated RTO will
never go below this value.
Initial RTO sets the RTO for the first communication try. Be careful: since all future tries are
based on this value, if you set it too low for network conditions, a connection will never be
made.
TCP Retransmits sets the number of times the device retries communication. Larger, busier
networks need a higher number of retransmits than smaller networks with less traffic.
TCP idle session timeout sets how long (in milliseconds) the device allows a session to
remain open without any activity. After this time, the device checks the session to make sure it
is still good, and closes it if it is not. The default is 240,000 milliseconds, or four minutes.
5. Click the Apply button to write your changes to the brain.
6. In the Operation Commands list, highlight Store configuration to flash. Click Send Command.
7. In the Operation Commands list, highlight Restart brain from powerup. Click Send Command.
The new TCP parameters are set.
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Index
A
accessing brain over the Internet, 10
ACT LED, 17
analog point
average filter weight, 20
clamping, 20
gain, 20
maximum value, 20
minimum value, 20
offset, 20
PID loop control, 20
ramping, 20
scaling, 20
TPO, 20
watchdog, 20
average filter weight, 20
B
blink codes, 25
brain
comparing features, 18
FTP, 21
installing, 8
networking, 13
Scratch Pad, 21
pinging the brain, 27
problems with, 26
simultaneously, 10
comparing brain feautures, 18
computer, connecting directly to brain, 14
connecting to brain
daisy-chaining, 15, 16
network interfaces, 15
troubleshooting, 26
counter, description, 19
D
daisy chain, 15, 16
data logging, 21
data mirroring, 21
default settings, restoring, 24
digital point
counter, 19
latching, 19
quadrature counter, 19
state, 19
TPO, 20
watchdog, 20
direct connection, 14
distributed system, 12
C
calibrating analog point, 20
clamping analog output point, 20
communicating with brain, 9
choosing methods, 11
E
email, 21
enterprise management system, 21
Ethernet network
accessing brain over the Internet, 10
attaching brain to existing network, 14
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certification, 30
daisy-chaining brains, 15
errors, 29
incorrect connections (diagram), 16
independent control network, 14
interfaces, 15, 17
troubleshooting, 29
event, 21
event messages, 21
F
failsafe bootloader mode, 24, 30
features
comparison of brain models, 18
descriptions of, 19
file system on brain, 21
firmware, loading, 24
FTP, 21
G
gain, definition, 20
generating
pulse, 20
square wave, 20
H
hardware, getting data about, 26
help
blink codes, 25
LED descriptions, 17
network problems, 29
Product Support, 4
high-density digital counter, 19
mounting rack, 6
quick start, 5
Internet, accessing brain over, 10
IP filtering, 21
L
latch, definition, 19
LEDs
blink codes, 25
description, 17
red, 27
LNK LED, 17
loop control on analog point, 20
M
maximum value, 20
measuring pulses, 20
memory map copying, 21
minimum value, 20
Modbus/TCP, 3, 9
mounting rack, installing, 6
N
network
architecture, 13
attaching brain to existing network, 14
certification, 30
daisy-chaining brains, 15
Ethernet errors, 29
incorrect connections (diagram), 16
independent, 14
interfaces, 15, 17
troubleshooting, 29
34
I
I/O modules
installing, 6
removing, 7
I/O point features, 19
installing
brain on rack, 8
I/O modules, 6
SNAP PAC Brains User’s Guide
O
off-latch, 19
off-pulse measurement, 20
offset, definition, 20
on-latch, 19
on-pulse measurement, 20
OPC, 3, 9
Opto 22 Product Support, 4
Page 39
OptoDataLink, 3, 10
OptoMMP, 3, 10
OptoOPCServer, 9
P
PAC Control, 3, 9
PAC Manager, 3, 9
peak, 20
PID loop control, 20
ping, 27
port access, limiting, 21
Product Support, 4
pulse
generation, 20
measurement, 20
Q
quadrature counter, 19
quick start, 5
R
rack for I/O modules, installing, 6
ramping analog output point, 20
removing I/O modules, 7
RESET button, 24, 30
restoring default settings, 24
retransmit timeout (RTO), 31
RSTP, 16
SNAP PAC System illustration, 12
SNAP-PAC-EB1, features, 18
SNAP-PAC-EB2, features, 18
SNMP, 21
square wave generation, 20
STAT LED, 17
state of digital point, 19
status conditions (blink codes), 25
STP, 16
system architecture, 13
T
TCP/IP
multiple sessions, 10
settings, 31
stack, 31
technical support, 4
thermocouple linearization, definition, 20
timed event, 21
timeout, 31
time-proportional output, 20
TPO, 20
troubleshooting
blink codes, 25
LED descriptions, 17
network, 29
Product Support, 4
V
valley, 20
S
scaling, description, 20
Scratch Pad areas, 21
security, 21
W
watchdog, definition, 20
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