OPTO 22 SNAP PAC Redundancy Option User Manual

SNAP PAC REDUNDANCY OPTION
USER’S GUIDE
Form 1831-180531—May 2018
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: [email protected]
Web: support.opto22.com
SNAP PAC Redundancy Option User’s Guide
Form 1831-180531—May 2018
Copyright © 2014–2017 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 newer 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. Refer to Opto 22 form
1042 for complete warranty information.
Wired+Wireless controllers and brains are licensed under one or more of the following patents: U.S. Patent No(s). 5282222,
RE37802, 6963617; Canadian Patent No. 2064975; European Patent No. 1142245; French Patent No. 1142245; British Patent
No. 1142245; Japanese Patent No. 2002535925A; German Patent No. 60011224.
Opto 22 FactoryFloor, groov, groov EPIC, Optomux, and Pamux are registered trademarks of Opto 22. Generation 4, groov
Server, ioControl, ioDisplay, ioManager, ioProject, ioUtilities, mistic, Nvio, Nvio.net Web Portal, OptoConnect, OptoControl,
OptoDataLink, OptoDisplay, OptoEMU, OptoEMU Sensor, OptoEMU Server, OptoOPCServer, OptoScript, OptoServer,
OptoTerminal, OptoUtilities, PAC Control, PAC Display, PAC Manager, PAC Project, PAC Project Basic, PAC Project Professional,
SNAP Ethernet I/O, SNAP I/O, SNAP OEM I/O, SNAP PAC System, SNAP Simple I/O, SNAP Ultimate I/O, and Wired+Wireless
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groov includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit. (http://www.openssl.org)
All other brand or product names are trademarks or registered trademarks of their respective companies or organizations.
Opto 22
Automation Made Simple.
ii
SNAP PAC Redundancy Option User’s Guide
Table of Contents
Chapter 1: Welcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Ethernet Link Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
System Architecture. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Redundancy Option Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SNAP-PAC-SRA Arbiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
SNAP-RPSW Redundant Power Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
PAC Control Professional and PAC Redundancy Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
About this Guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Related Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Product Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Chapter 2: Connecting the Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
What You Will Need. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Configuration Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Connecting the PAC S-series Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Connecting SNAP-PAC-S2 Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Connecting SNAP-PAC-S1 Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Wiring the 7-pin Serial Connector on SNAP-PAC-S2 Controllers . . . . . . . . . . . . . . . . . . . . . . . .13
Wiring the 10-pin Serial Connector on SNAP-PAC-S1 Controllers . . . . . . . . . . . . . . . . . . . . . . .13
Wiring the 6-pin Serial Connector on the Arbiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Connecting Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Power Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Chapter 3: Configuring a Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
What You Will Need. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Assigning a Primary IP Address to ENET 1 on each Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Assigning an IP Address to the Arbiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Creating a Control Engine for Controller Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Commissioning the Controllers for Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Checking the System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
SNAP PAC Redundancy Option User’s Guide
iiiiii
Chapter 4: Creating a Strategy with Controller Redundancy . . . . . . . . . . . . . . . . . . . . 31
Glossary of Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Persistent/Redundant Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Redundant Control Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Sequential Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Sync Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Transaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Transactional Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Creating a Redundant Strategy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Step 1. Enabling the PAC Control Redundancy Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Step 2. Adding a Redundant Control Engine to a PAC Control Strategy . . . . . . . . . . . . . . . . 36
Adding an Existing Redundant Control Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Configuring an Existing Control Engine for Redundancy . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Step 3. Configuring Persistent/Redundant Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Persistent/Redundant Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Configuring Redundant Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Step 4. Designing a Transactional Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
Transaction Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Design Considerations and Chart Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Using Reads and Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
What Causes Synchronization to Occur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Adding a Sync Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Chapter 5: System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Checking System Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Redundant System Status Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Using the Memory Map to Read Status Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Using the Memory Map to Enter and Exit Maintenance Mode . . . . . . . . . . . . . . . . . . . . . 50
Entering Maintenance Mode on Boot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Redundant System State Machine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Changing an IP Address on a Device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
Installing New Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Installing Firmware to the Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Using the Running System Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Using the Controller Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Installing Firmware to the Arbiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Managing Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Using Advanced Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Using Controller Redundancy – Debug Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
Arbiter Status LEDs and Blink Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Communication Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
System Status LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Resetting the Arbiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
iv
SNAP PAC Redundancy Option User’s Guide
1: 1: WelcomeChapter 1
1: Welcome
Welcome to the SNAP PAC Redundancy Option User’s Guide. Inside you’ll find instructions on how to
set up redundant controllers using two perfectly matched SNAP-PAC-S controllers. This guide
assumes that you understand fully how to use PAC Control™ and have some familiarity with
Opto 22’s SNAP PAC System™.
In This Chapter
Introduction ..................................................................... 1
System Architecture ..................................................... 2
Redundancy Option Components......................... 3
About this Guide............................................................ 5
Related Documentation ............................................. 5
Product Support............................................................. 5
Introduction
While Opto 22 Ethernet-based control systems are extremely reliable, no control system is perfect.
However, with properly configured redundant controllers, in the unlikely event that a controller were
to fail for whatever reason, a second identically configured controller takes over with almost no
down time. The SNAP PAC Redundancy Option provides the tools for developing a control system
with an increased level of reliability that can survive single points of failure, and it can improve your
system’s mean time between failures (MTBF).
A SNAP PAC System configured with the SNAP PAC Redundancy Option includes:
•
Two identically matched S-series PACs
•
A SNAP-PAC-SRA arbiter, a hardware device that controls which controller is active based on
status information returned by each controller in response to the arbiter’s periodic heartbeat
requests. See “SNAP-PAC-SRA Arbiter” on page 3.
•
A SNAP-RPSW redundant power switch connected to the arbiter and both controllers. This
switch responds to the supply-voltage output from the arbiter, which allows it to reliably restart
a controller. See “SNAP-RPSW Redundant Power Switch” on page 4.
SNAP PAC Redundancy Option User’s Guide
11
SYSTEM ARCHITECTURE
NOTE: The SNAP-PAC-SRA arbiter and the SNAP-RPSW redundant power switch can be purchased
together in the SNAP PAC Redundancy Option Kit, part number SNAP-PAC-ROK.
•
One or more Opto 22 SNAP PAC Ethernet brain-based I/O units on the same Ethernet network
as the controllers
•
A PAC Control Professional strategy for use on the system’s two redundant controllers that
includes special features such as sync blocks and persistent/redundant variables. (See Chapter 4
on page 31.) Included with PAC Control Pro is the PAC Redundancy Manager, a software utility
you can use to configure and monitor the redundant PAC S-series controllers and the
SNAP-PAC-SRA arbiter.
Ethernet Link Redundancy
This guide describes only how to set up redundant controllers for your system, not Ethernet link
redundancy, which is also offered by Opto 22. Using PAC Project Professional, Ethernet link
redundancy allows you to configure redundant networks for your control system. This is achieved in
part by assigning a primary IP address to one Ethernet interface on a PAC S or PAC R controller, and a
secondary IP address to the controller’s other Ethernet interface. If communication to the primary
address fails, the secondary address takes over.
There are two basic ways to use Ethernet link redundancy:
•
HMI-to-controller link redundancy, which is not supported when using redundant controllers.
For more information, see form 1700, the PAC Control User’s Guide, and form 1702, the PAC
Display User’s Guide.
•
Controller-to-I/O link redundancy, which is supported when using redundant controllers. For
more information, see form 1700, the PAC Control User’s Guide.
NOTE: When using controller-to-I/O link redundancy, you must connect ENET 2 on the controllers and
I/O units to a switch. No other devices can be connected to that switch.
System Architecture
In the following simplified illustration of the redundancy architecture, two SNAP-PAC-S2 controllers
are connected via Ethernet to the same I/O. A SNAP-PAC-SRA arbiter is connected to both
controllers with dedicated RS-485 links. An Ethernet crossover cable connected to the ENET 2
Ethernet ports enables communication between the controllers. A SNAP-RSPW redundancy power
switch connected to the arbiter controls power to the controllers. Separate power supplies for the
arbiter and each of the controllers are not shown.
2
SNAP PAC Redundancy Option User’s Guide
CHAPTER 1: WELCOME
PAC Control Pro with Redundancy Manager
SNAP PAC brain and I/O
N-TRON Switch
RS-485
Ethernet crossover
cable connects the
PAC S2s on ENET 2
Redundant power switch
Arbiter
Power control Power
RS-485
2 PAC S-series
controllers
Redundancy Option Components
The Redundancy Option components—S-series PACs, SNAP-PAC-SRA arbiter, and SNAP-RPSW
redundant power switch—are described below.
SNAP-PAC-SRA Arbiter
The SNAP-PAC-SRA arbiter is a stand-alone unit that monitors the
operation of the PAC S-series controllers connected to it via a
dedicated RS-485 link. If the arbiter detects improper operation of
the primary controller, the arbiter switches control to the secondary
controller. The SNAP-PAC-SRA arbiter is responsible for:
•
Maintains the active/backup status of each controller in a
redundant Opto 22 system
•
Sends heartbeat requests at regular intervals to each controller
in order to receive status information
•
Based on the status information, sends messages that make
one controller active and put the other controller in backup
mode
•
Signals the backup controller to qualify itself to be ready to take over as the active controller.
The qualification process includes matching the firmware and strategy to those on the active
SNAP PAC Redundancy Option User’s Guide
33
REDUNDANCY OPTION COMPONENTS
controller, and updating redundant variables and I/O values. If neither controller is qualified, the
arbiter favors controller #1 if both are started up within one second of each other.
•
When a controller is disqualified, the arbiter tells the controller to reset itself.
•
Manages the power supply of each controller using a supply-voltage output to drive
normally-closed relays in the SNAP-RPSW redundant power switch. This allows the arbiter to
reliably restart a controller ensuring that I/O never has more than one master.
SNAP-RPSW Redundant Power Switch
The SNAP-RPSW redundant power switch is a relay device designed
especially for use in a SNAP PAC redundant system. Connected to
the SNAP-PAC-SRA arbiter and both controllers, this switch responds
to the supply-voltage output from the arbiter. This allows a
controller to be restarted in order to bring the controller back up, or
to re-commission the controller after its firmware has been updated.
PAC Control Professional and PAC
Redundancy Manager
The controllers in a redundant system run a control program built
with PAC Control™ Professional, one component of PAC Project™
Professional software. Also included with PAC Project Pro, the PAC
Redundancy Manager provides tools to configure the arbiter, monitor the devices in a redundant
system, install firmware on the arbiter and the controllers, and more.
4
SNAP PAC Redundancy Option User’s Guide
CHAPTER 1: WELCOME
About this Guide
Chapter 1: Welcome—Introduces the SNAP PAC Redundancy Option, provides information about
this guide, where to find additional information, and how to reach Opto 22 Product Support.
Chapter 2: Connecting the Hardware—Describes how to connect the serial, Ethernet, and power
cables for critical devices used in a redundant system.
Chapter 3: Configuring a Control System—Provides instructions on how to use PAC Control, PAC
Manager, and the SNAP-PAC Arbiter to configure the controllers and arbiter.
Chapter 4: Creating a Strategy with Controller Redundancy—Describes how to use the Redundancy
Option features in PAC Control to create a transactional chart.
Chapter 5: System Maintenance—Describes how to change an IP address on a controller or arbiter,
load new firmware, reset the arbiter, use the PAC Redundancy Manager advanced features, and
various other system maintenance tasks.
Related Documentation
For more information on topics related to the SNAP PAC Redundancy Option, see the following
Opto 22 documents.
For this information
See this guide
Form
How to install and use SNAP PAC S-series
controllers
SNAP PAC S-Series Controller User’s Guide
1592
How to install and use PAC Control
PAC Control User’s Guide
1700
Detailed information about each command
(instruction) available in PAC Control
PAC Control Command Reference
1701
All documents are available on our website, www.opto22.com. The easiest way to find a document
is to follow the link above or search on its form number.
Product Support
If you have any questions about using SNAP PAC Redundancy Option, you can call, fax, or email
Opto 22 Product Support. Product support is free.
Phone:
800-TEK-OPTO (800-835-6786 toll-free
in the U.S. and Canada)
951-695-3080
Monday through Friday,
7 a.m. to 5 p.m. Pacific Time
Fax:
951-695-3017
Email:
[email protected]
Opto 22 website:
www.opto22.com
NOTE: Email messages and phone
calls to Opto 22 Product Support
are grouped together and
answered in the order received.
SNAP PAC Redundancy Option User’s Guide
55
PRODUCT SUPPORT
When calling for technical support, be prepared to provide the following information about your
system to the Product Support engineer:
•
PC configuration (type of processor, speed, memory, and operating system)
•
Software and version being used
•
Controller firmware version
•
A complete description of your hardware and operating systems, including:
– switch configuration
– type of power supply
– types of I/O units installed
– third-party devices installed (for example, barcode readers)
•
Specific error messages seen.
6
SNAP PAC Redundancy Option User’s Guide
2: 2: Connecting the HardwareChapter 2
2: Connecting the Hardware
This chapter describes how to connect the serial, Ethernet, and power cables for the components
used in a redundant system, including the SNAP PAC S-series controllers, the SNAP-PAC-SRA arbiter,
and the SNAP-RPSW redundant power switch. It also introduces a few basic configuration scenarios.
In This Chapter
What You Will Need ...................................................... 7
Configuration Scenarios ............................................. 8
Connecting the PAC S-series Controllers............. 9
Connecting Power ......................................................14
What You Will Need
•
A PC running PAC Control Professional 9.0 or higher
•
A crossover cable to connect the two controllers.
•
10BASE-T or 100BASE-TX Ethernet network
•
The SNAP PAC Redundancy Option Kit, part number SNAP-PAC-ROK, which includes a
SNAP-PAC-SRA arbiter and a SNAP-RPSW redundant power switch
•
Three SNAP-PS24 power supplies
•
A functioning Ethernet-based SNAP PAC control system that includes:
– Two SNAP PAC S-series controllers that are exactly the same model, such as two
SNAP-PAC-S2s or two SNAP-PAC-S2-Ws, with firmware R9.0a or higher and loader R6.0a or
higher
– One or more Opto 22 SNAP PAC Ethernet brain-based I/O units on the same Ethernet
network as the controllers
– PAC Control strategy developed for use on the system’s two redundant controllers. See
Chapter 4 on page 31 for information on how to develop a strategy for controller
redundancy.
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CONFIGURATION SCENARIOS
Configuration Scenarios
As shown below there are three basic configuration scenarios. Depending on the level of protection
you require at your site, you may want to place the controllers in the same cabinet or in different
cabinets. Or you might want to put the arbiter in a different room or cabinet.
Keep the following things in mind when deciding how to configure your system:
•
The system will continue to run if any single component fails or in any situation where the
currently active controller does not fail and can still communicate to I/O.
•
If both the arbiter and the active controller fail simultaneously, or if the active controller fails
while the arbiter is already down, the backup will not be able to take over.
Scenario 1: Controllers and arbiter are in the same cabinet
Scenario 2: Controller 1 and Controller 2 are in separate cabinets or rooms, and the arbiter
is placed in the same cabinet or room as one of the controllers
Scenario 3: Controller 1, Controller 2, and the arbiter are in separate cabinets or rooms
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CHAPTER 2: CONNECTING THE HARDWARE
Connecting the PAC S-series Controllers
As shown here, two SNAP PAC S-series controllers connect to the arbiter using RS-485 serial ports.
They connect to each other on ENET 2 with an Ethernet crossover cable. See directions below for
either PAC S2s or PAC S1s. See also the diagram on page 2.
Serial connections
Ethernet connections
ENET 2
ENET 1
To network
SNAP-PAC-S2 #1
Serial 2
CTR1
Crossover cable
SNAP-PAC-S2 #2
CTR2
Serial 2
This section includes the following topics:
•
“Connecting SNAP-PAC-S2 Controllers” on page 10
•
“Connecting SNAP-PAC-S1 Controllers” on page 11
•
“Wiring the 7-pin Serial Connector on SNAP-PAC-S2 Controllers” on page 13
•
“Wiring the 10-pin Serial Connector on SNAP-PAC-S1 Controllers” on page 13
•
“Wiring the 6-pin Serial Connector on the Arbiter” on page 14
For pinouts of SNAP PAC S-series controllers, see form 1592, the SNAP PAC S-Series User’s Guide.
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CONNECTING THE PAC S-SERIES CONTROLLERS
Connecting SNAP-PAC-S2 Controllers
See also “Wiring the 7-pin Serial Connector on SNAP-PAC-S2 Controllers” on page 13 and “Wiring
the 6-pin Serial Connector on the Arbiter” on page 14.
1. Using ENET 2 on both controllers, connect the controllers to each other with a crossover cable.
To network
ENET 2
ENET 1
Crossover cable
NOTE: While not recommended, you can instead use a straight through cable to connect each
controller’s ENET 2 to your control network.
2. Using ENET 1, connect the controllers to the network.
3. Connect Serial 2 on Controller 1 to CTR1 on the arbiter using RS-485, “2-wire” mode.
4. Connect Serial 2 on Controller 2 to CTR2 on the arbiter using RS-485, “2-wire” mode.
Pin 1
Red + Black –
TX/RX –
Common
TX/RX +
TX/RX +
TX/RX –
Common
ENET 1
Serial 2
Chassis GND
ENET 2
Controller
Arbiter
CTR1 and CTR2
Controller
Serial 2
NOTES on RS-485, “2-wire” mode:
• Correct RS-485 “2-wire” mode requires a single
twisted pair for the data wires and an additional
insulated wire for the signal common connection.
• It is usually easiest to use a two-pair (shielded) RS-485
data cable, as follows:
- One pair for data
- One pair for signal common
- Shield for chassis ground.
• Do NOT connect the signal common to chassis
ground.
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CTR1
CTR2
Arbiter
CHAPTER 2: CONNECTING THE HARDWARE
Connecting SNAP-PAC-S1 Controllers
See also “Wiring the 10-pin Serial Connector on SNAP-PAC-S1 Controllers” on page 13 and “Wiring
the 6-pin Serial Connector on the Arbiter” on page 14.
1. Using ENET 2 on both controllers, connect the controllers to each other with a crossover cable.
ENET 2
To network
ENET 1
Crossover cable
2. Using ENET 1, connect the controllers to the network.
3. Connect Serial 2 on Controller 1 to CTR1 on the arbiter using RS-485, “2-wire” mode.
4. Connect Serial 2 on Controller 2 to CTR2 on the arbiter using RS-485, “2-wire” mode.
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CONNECTING THE PAC S-SERIES CONTROLLERS
ENET 2
ENET 1
Serial 2
Pin 1
Red + Black –
TX/RX –
Common
TX/RX +
TX/RX +
TX/RX –
Common
Chassis GND
Arbiter
CTR1 and CTR2
Controller
Serial 2
Controller
NOTES on RS-485, “2-wire” mode:
• Correct RS-485 “2-wire” mode requires a single
twisted pair for the data wires and an additional
insulated wire for the signal common connection.
• It is usually easiest to use a two-pair (shielded) RS-485
data cable, as follows:
- One pair for data
- One pair for signal common
- Shield for chassis ground.
• Do NOT connect the signal common to chassis
ground.
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CTR1
CTR2
Arbiter
CHAPTER 2: CONNECTING THE HARDWARE
Wiring the 7-pin Serial Connector on SNAP-PAC-S2
Controllers
Each serial port on the SNAP-PAC-S2 uses a 7-pin pluggable connector supplied with the controller
(EBY part number EB1381M-07-500 or equivalent). Use the screws on the side of the connector to
insert or remove wires.
CAUTION: Do not use communication port connectors from a legacy OptoControl controller*. Legacy
connectors will fit in a SNAP-PAC-S2, but the pin orientation is different. Instead, use the connectors
supplied with the SNAP-PAC-S2 controller.
*Legacy OptoControl Controllers
G4LC32
G4LC32SX
G4LC32ISA
G4LC32ISA-LT
M4
M4IO
M4RTU
SNAP-LCM4
SNAP-LCSX/PLUS
Wiring the 10-pin Serial Connector on SNAP-PAC-S1
Controllers
Serial ports 1 and 2 on SNAP-PAC-S1 controllers share a 10-pin pluggable connector (Phoenix
Contact, part number FK-MC 0.5 - 2.5, supplied with the controller).
When inserting and removing wire leads into this connector:
1. Completely depress the small orange tab for the appropriate opening with a small screwdriver.
2. While holding the tab down with the screwdriver, insert or remove the wire as needed.
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CONNECTING POWER
3. Release the orange tab.
Pin 1
Hole
Orange tab
Wiring the 6-pin Serial Connector on the Arbiter
The RS-485 serial ports on the SNAP-PAC-SRA arbiter use a 6-pin pluggable connector (Phoenix
Contact, part number FK-MC 0,5/06 - 2.5, supplied with the arbiter). When inserting and removing
wire leads into this connector:
1. Completely depress the small orange tab for the appropriate opening with a small screwdriver.
2. While holding the tab down with the screwdriver, insert or remove the wire as needed.
3. Release the orange tab.
Hole
Orange tab
Connecting Power
Using the Power Connection Diagram on page 15, connect power to the arbiter, controllers, and
switch as follows:
1. Connect one of the three SNAP-PS24 power supplies to the SNAP-PAC-SRA arbiter.
2. Connect a power supply to Side 1 of the SNAP-RPSW switch.
3. Connect a power supply to Side 2 of the switch.
4. Connect power from Side 1 on the switch to Controller 1.
5. Connect power from Side 2 on the switch to Controller 2.
6. Connect control wires from the arbiter to Side 1 and Side 2 on the switch.
Now you are ready to configure the redundant system devices. Go the next chapter,
Chapter 3: Configuring a Control System.
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CHAPTER 2: CONNECTING THE HARDWARE
Power Connection Diagram
red/white wire (+)
black/white wire
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CONNECTING POWER
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SNAP PAC Redundancy Option User’s Guide
3: 3: Configuring a Control SystemChapter 3
3: Configuring a Control
System
This chapter describes how to use PAC Control and the PAC Redundancy Manager to configure the
controllers and arbiter.
In This Chapter
What You Will Need ........................................................................................................17
Assigning a Primary IP Address to ENET 1 on each Controller ....................17
Assigning an IP Address to the Arbiter ..................................................................21
Creating a Control Engine for Controller Redundancy ...................................24
Commissioning the Controllers for Redundancy ..............................................26
What You Will Need ........................................................................................................28
What You Will Need
•
Two PAC S-series controllers and the components included with the Redundancy Option Kit
connected as described in “2: Connecting the Hardware” on page 7
•
PAC Project Professional 9.0 installed on a PC connected to the control network
Assigning a Primary IP Address to ENET 1 on each Controller
Each device must have a valid IP address and subnet mask so that it can communicate on the
network. If your controllers already have valid primary IP addresses, you can skip to the next section,
“Assigning an IP Address to the Arbiter” on page 21.
When you start a SNAP PAC S-series controller that does not have an IP address, it starts in BootP
mode, which means it sends out a BootP broadcast requesting an IP address. This is indicated by a
quickly blinking status light.
You respond to the BootP broadcast by using the PAC Redundancy Manager or PAC Manager to
assign a static IP address and subnet mask. If the network you're using has a Dynamic Host
Configuration Protocol (DHCP) server, either assign a static IP address before connecting the device
to the network (preferred), or disable the server. (These servers may respond to BootP requests and
assign a dynamic address.)
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ASSIGNING A PRIMARY IP ADDRESS TO ENET 1 ON EACH CONTROLLER
If the device is not currently in BootP mode, see form 1592, the SNAP PAC S-Series Controllers User’s
Guide, to reset the controller.
SNAP PAC S-series controllers each have two separate Ethernet network interfaces; Wired+Wireless
models have an additional wireless interface. Each interface has a separate MAC address and
therefore takes a separate, unique IP address. However, only ENET 1 sends a BootP request. Once you
have assigned the primary IP address to ENET 1, you can assign the secondary address to ENET 2.
ENET 1 is used to communicate on the Ethernet network. ENET 2 is used by the controllers to
communicate with each other.
NOTE: BootP broadcasts cannot get through a firewall in the PC where PAC Manager is running. Make sure
any firewall in the computer (such as the built-in firewall in Windows) is disabled before you try to assign
IP addresses. Firewalls in a router should not be a problem.
1. Make sure that the Opto 22 hardware is connected according to the instructions in
Chapter 2: Connecting the Hardware, and that the PAC Control Pro software is installed on
the PC.
2. Make sure you know the MAC address of the S-series controller.
The MAC address is on a label on the side of the device.
3. Turn on the Opto 22 device(s).
4. On the PC, select StartProgramsOpto 22PAC Project Software
PAC Redundancy Manager.
5. In the Menu area on the left, under Tasks & Tools > General Tools, click Assign IP Address.
The following dialog box appears. Any Opto 22 Ethernet-based devices without IP addresses
that are on the PC’s network segment appear in the list of units requesting IP addresses.
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CHAPTER 3: CONFIGURING A CONTROL SYSTEM
NOTE: If no MAC address appears, check the following:
•
Is the controller turned on?
•
Is it correctly connected to an Ethernet hub using a straight-through cable? Is the PC on the same
subnet as the controller? See the PC’s user’s guide for networking information.
•
Does the controller already have an IP address? To change the IP address, see “Changing an IP
Address on a Device” on page 52.
•
Is the controller booting to the loader rather than the firmware? (See the controller user’s guide.)
•
Does the PC have firewall software that blocks network broadcasts? If so, disable the software.
6. Click Select Device next to the MAC address of the controller.
CAUTION: PAC Redundancy Manager lists ALL Opto 22 devices sending BootP or DHCP broadcasts.
Assign an IP addresses only to the controller!
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ASSIGNING A PRIMARY IP ADDRESS TO ENET 1 ON EACH CONTROLLER
The MAC address appears in the MAC Address text box:
MAC address
7. Enter the IP Address and the Subnet Mask for the device. Leave the gateway address all zeros,
0.0.0.0. Leave the DNS address at 0.0.0.0 and the Host Name field blank.
CAUTION: Each device on your network, including computers, routers, controllers, brains, and so on,
must have a unique IP address. Failure to assign unique IP addresses may cause catastrophic network
or hardware failures. If you don’t know which IP addresses are safe to use, check with your system
administrator.
8. When the IP address, subnet mask, and other fields are correct, click Assign IP Address.
Progress is shown at the bottom of the screen.
Progress
9. When all items user Progress are checked, click Done.
10. Repeat steps 5 through 9 for Controller 2.
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CHAPTER 3: CONFIGURING A CONTROL SYSTEM
Now you are ready to assign an IP address to the arbiter as described in the next section.
Assigning an IP Address to the Arbiter
NOTE: This section details how to assign an IP address to the arbiter for the first time. If your arbiter already
has an IP address and you want to change it, see “Changing an IP Address on a Device” on page 52.
Each arbiter ships from the factory with a unique hardware Media Access Control (MAC) address and
with a default IP address of 0.0.0.0, which is invalid. The arbiter must have a valid IP address and
subnet mask so that it can communicate on the network. You can do this using either PAC Manager
or the PAC Redundancy Manager. The following instructions are for the PAC Redundancy Manager.
NOTE: In order to assign IP addresses, you must be logged in with administrative rights.
When you start a SNAP-PAC-SRA arbiter that does not have an IP address, it starts in BootP mode,
which means it sends out a BootP broadcast requesting an IP address. This is indicated by a quickly
blinking status light.
Arbiter status light
If the device is not currently in BootP mode, see “Resetting the Arbiter” on page 62 to restore factory
default settings.
NOTE: BootP broadcasts cannot get through a firewall in the PC where PAC Manager is running. Make sure
any firewall in the computer (such as the built-in firewall in Windows) is disabled before you try to assign
IP addresses. Firewalls in a router should not be a problem.
You respond to the BootP broadcast by using the PAC Redundancy Manager or PAC Manager to
assign a static IP address and subnet mask. If the network you're using has a Dynamic Host
Configuration Protocol (DHCP) server, either assign a static IP address before connecting the device
to the network (preferred), or disable the server. (These servers may respond to BootP requests and
assign a dynamic address.)
NOTE: To make sure the arbiter is not on a network with a DHCP server, we recommend you use a crossover
cable with a direct connection to assign IP addresses. If you connect directly to a PC that is normally on a
DHCP network, be aware that you must assign a fixed IP address to the PC’s network card (NIC) in order to
communicate.
1. Make sure that the Opto 22 hardware is connected according to the instructions in
Chapter 2: Connecting the Hardware, and that the PAC Control Pro software is installed on
the PC.
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ASSIGNING AN IP ADDRESS TO THE ARBITER
2. Make sure you know the MAC address of the SNAP-PAC-SRA arbiter.
The MAC address is on a label on the side of the device.
3. Turn on the SNAP-PAC-SRA arbiter.
4. On the PC, select StartProgramsOpto 22PAC Project Software
PAC Redundancy Manager.
The PAC Redundancy Manager opens.
5. In the Menu area, click Assign IP Address.
The following dialog box appears. Any Opto 22 Ethernet-based devices without IP addresses
that are on the PC’s network segment appear in the list of units requesting IP addresses.
NOTE: If no MAC address appears, check the following:
•
Is the arbiter turned on?
•
Is it correctly connected to the PC using a crossover cable or correctly connected to an Ethernet
hub using a straight-through cable? Is the PC on the same subnet as the arbiter? See the PC’s
user’s guide for networking information.
•
Does the arbiter already have an IP address? To change the IP address, see “Changing an IP
Address on a Device” on page 52.
•
Does the PC have firewall software that blocks network broadcasts? If so, disable the software.
6. Click Select Device next to the MAC address of the arbiter.
CAUTION: PAC Manager lists ALL Opto 22 devices sending BootP or DHCP broadcasts. Assign an IP
addresses only to the arbiter!
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The MAC address appears in the MAC Address text box:
MAC address
7. Enter the IP Address and the Subnet Mask for the device. Leave the gateway address all zeros
(0.0.0.0). Leave the DNS address at 0.0.0.0 and the Host Name field blank.
CAUTION: Each device on your network, including computers, routers, controllers, brains, and so on,
must have a unique IP address. Failure to assign unique IP addresses may cause catastrophic network
or hardware failures. If you don’t know which IP addresses are safe to use, check with your system
administrator.
8. When the IP address, subnet mask, and other fields are correct, click Assign IP Address.
Progress is shown at the bottom of the screen.
Progress
9. When all items under Progress are checked, click Done.
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CREATING A CONTROL ENGINE FOR CONTROLLER REDUNDANCY
Now you are ready to create a redundant control engine to use in your strategy, as described in
the next section.
Creating a Control Engine for Controller Redundancy
The instructions below describe how to create a control engine to use with a redundant controller
system. These instructions are for PAC Redundancy Manager. You can also create a control engine
using PAC Control. For basic information on how to define a control engine, see form 1700, the PAC
Control User’s Guide and “Configuring an Existing Control Engine for Redundancy” on page 37 of this
guide.
1. Make sure you have connected the hardware as described in Chapter 2: Connecting the
Hardware.
2. Make sure you have completed all of the procedures in the previous sections of this chapter.
3. In PAC Redundancy Manager, under Redundant Control Engines, click “Edit list with PAC
Terminal” to open PAC Terminal.
Add
4. In the PAC Terminal window, under Configure Control Engines, click Add to open the Control
Engine Configuration dialog box.
5. Enter a descriptive name for the control engine.
Valid characters are letters, numbers, spaces, and most other characters except colons and
square brackets. Spaces cannot be used as first or last characters.
6. Under System Type, select Redundant Controllers.
New Settings options appear.
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CHAPTER 3: CONFIGURING A CONTROL SYSTEM
7. Using the IP addresses you created earlier, enter the IP address for Controller 1, Controller 2, and
the Arbiter, then click OK.
For information on assigning IP addresses, see “Assigning a Primary IP Address to ENET 1 on
each Controller” on page 17 and “Assigning an IP Address to the Arbiter” on page 21.
The completed dialog box will look something like this:
8. For Controller Port, Software Retries, and Software Timeout, use the default settings:
Controller Port: 22001
Software Retries: 0
Software Timeout: 5000 msec
9. Click OK, and then exit PAC Terminal.
10. In PAC Redundancy Manager, under Redundant Control Engines, click Refresh.
The control engine you created with redundant controllers appears under Redundant Control
Engines.
New redundant
control engine
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COMMISSIONING THE CONTROLLERS FOR REDUNDANCY
Additional configuration options are described in “Using Controller Redundancy – Debug Options”
on page 60.
Now you are ready to commission the controllers for redundancy as described in the next section.
Commissioning the Controllers for Redundancy
SNAP PAC S-series controllers have two independent Ethernet network interfaces, labeled on the
top of the controller as ENET 1 and ENET 2. The controller sends its initial BootP request from ENET 1,
and the IP address you assign to the controller is for this primary interface.
The two PAC S controllers in a redundant system communicate with each other using the secondary
IP address over ENET 2. In order to assign the secondary address, you must first assign the primary
address. See “Assigning a Primary IP Address to ENET 1 on each Controller” on page 17.
When assigning the secondary addresses for ENET 2 on each controller, make sure that the
secondary address for Controller 1 is even, such as 172.22.22.2; make sure the secondary address for
Controller 2 is odd, such as 172.22.22.3. Also, the two IP addresses must be sequential, such as the
examples, 172.22.22.2 and 172.22.22.3.
To assign the secondary IP for ENET 2, follow the steps below.
NOTE: If you need to configure or modify settings for the network interface cards on your PC, you must be
logged in with administrative rights.
1. Make sure that Controller 1 and Controller 2 are both connected according to the instructions
in Chapter 2: Connecting the Hardware, and that both controllers are turned on.
2. Make sure that the PAC Project software is installed on the PC.
3. Make sure that you have assigned a primary IP address to ENET 1 for both Controller 1 and
Controller 2, and that you know these addresses. For more information, see “Assigning a
Primary IP Address to ENET 1 on each Controller” on page 17.
4. Make sure that you have created a redundant control engine that uses the IP addresses of the
controllers and arbiter that you want to commission. See page 24.
NOTE: The following instructions are for PAC Redundancy Manager. However, you can use PAC Terminal to
commission the controllers for redundancy.
5. In PAC Redundancy Manager, under Tasks & Tools > Controller Management, click Commission
for Redundancy.
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6. Select Controller 1, and click “read the current settings” to see if the controller is already set up
for redundancy. If it is, skip to step 8.
NOTE: If the PAC Redundancy Manager cannot find the address, you will receive an error message. If
you receive an error message, check the following:
•
Did you enter the IP address correctly when you created the control engine?
•
Is the controller turned on?
•
Is the controller correctly connected to an Ethernet hub using a straight-through cable? Is the PC
on the same subnet as the controller? See the PC’s user’s guide for networking information.
7. Enter a secondary IP address and subnet for ENET 2 of Controller 1.
The ENET 2 port is used to connect the controllers to each other. The recommended settings
for ENET 2 for Controller 1 are as follows:
– Secondary IP Address: 172.22.22.2
– Subnet Mask: 255.255.255.240
NOTE: Make sure the secondary address for Controller 1 is even, such as 172.22.22.2. And, make sure
the secondary address for Controller 2 is odd, such as 172.22.22.3. In addition, the two IP addresses
must be sequential, such as 172.22.22.2 and 172.22.22.3.
8. Select Controller 2 and repeat the steps above for the second controller.
The recommended settings for ENET 2 for Controller 2 are as follows:
– Secondary IP Address: 172.22.22.3
– Subnet Mask: 255.255.255.240
9. When all the secondary IP address fields are correct, click Apply Settings.
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CHECKING THE SYSTEM
The information is sent to the SNAP PACs.
10. Note the progress as the settings are applied, the device reset, and the process is completed.
11. Click Done at the bottom of the dialog box.
Now you are ready to add the configured and commissioned system to a strategy. See the next
chapter, Chapter 4: Creating a Strategy with Controller Redundancy.
Checking the System
Use System Checkout in PAC Redundancy Manager to confirm that your system is configured and
connected correctly.
CAUTION: Be careful if you use this feature on a system that is currently running a process. During the
system check, the first PAC is checked and the second PAC’s strategy is cleared; then the strategy from the
first PAC is copied to the second PAC, and the second PAC is checked.
1. Under Task & Tools > System Management, simply click System Checkout.
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A green check indicates that a test was passed successfully. A red X indicates that a problem
was found.
2. If a problem is detected, follow the on-screen directions to correct the problem. (Remember
that a strategy must be running on the controller in order for the check to work.)
3. Click System Checkout again.
If your system is properly configured, the results screen looks like this:
Now you are ready to create a strategy designed for controller redundancy. See the next chapter,
Chapter 4: Creating a Strategy with Controller Redundancy
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CHECKING THE SYSTEM
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4: 4: Creating a Strategy with Controller RedundancyChapter 4
4: Creating a Strategy with
Controller Redundancy
This chapter describes how to set up a PAC Control Pro strategy for controller redundancy.
Redundant controllers are configured identically. This means that they are programmed with the
same strategy, they run in lockstep with each other, and their variables and I/O have the same
values. The Active controller is in charge and informs the Backup controller of its state. This is
achieved by the Active controller telling the Backup controller every time it changes a variable, I/O,
or moves to the next instruction or flowchart block. PAC Control provides extra control for the
strategy programmer to reduce the communication overhead of synchronization; only
persistent/redundant variables and I/O are synchronized, and by using sync blocks, synchronization
is delayed until a sync block is encountered in a transactional chart.
In This Chapter
Glossary of Terms ................................................................................................................................31
Creating a Redundant Strategy ....................................................................................................33
Step 1. Enabling the PAC Control Redundancy Features........................................33
Step 2. Adding a Redundant Control Engine to a PAC Control Strategy .........33
Step 3. Configuring Persistent/Redundant Data ........................................................39
Step 4. Designing a Transactional Chart.........................................................................41
Glossary of Terms
Persistent/Redundant Data
Data generated by persistent/redundant variables that are replicated to an available backup
controller whenever synchronization occurs. See Chapter 4: Creating a Strategy with Controller
Redundancy.
Redundant Control Engine
A control engine configured for redundant controllers. See “Creating a Control Engine for Controller
Redundancy” on page 24.
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GLOSSARY OF TERMS
Sequential Programming
The method of programming used in a PAC Control chart. A sequentially programmed chart starts at
one block and proceeds sequentially through command blocks to the end using variables, inputs,
and outputs.
Sync Block
A block type in PAC Control used only for redundant strategies. When a sync block is encountered in
a chart, the data generated by the chart is synchronized in both the active and backup controllers.
The sync block also indicates to the backup controller what state the chart is in
(running/stopped/paused) and where in the logic to begin in case the active controller fails. A chart
that uses sync blocks is called a transactional chart (see the glossary entry below).
When a sync block is placed in a chart, this tells the controller not to do any writes (in that chart) to
any I/O or persistent/redundant variables until it encounters a sync block. All the various kinds of
writes that occur in a chart after a sync block are not executed until the next sync block is
encountered. In this way both controllers know what points/variables have been written to.
Sync block
For more information, see “What Causes Synchronization to Occur” on page 45.
Transaction
While the term “transaction,” is borrowed from the transactional database world, for our purposes, a
transaction is a collection of redundant operations that are logged and deferred until a sync block is
encountered, at which point the data generated by a transactional chart is synchronized in both the
active and backup controllers. Each transaction starts with the first write of a persistent/redundant
variable or I/O, and it ends with a sync block.
Transactional Chart
A special PAC Control chart used to support persistent/redundant data with redundant controllers. A
transactional chart always includes at least one sync block, which is used to define a transaction (see
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definition above) within the logic. A transactional chart is usually sequential; it starts at one block
and proceeds sequentially through command blocks to the end using variables, inputs, and outputs.
Creating a Redundant Strategy
When you create a strategy for controller redundancy, most tasks such as configuring I/O,
programming with commands, using PID loops and so on are exactly the same as for a
non-redundant strategy. (See form 1700, the PAC Control User’s Guide, for more information on
creating a strategy in PAC Control.)
What makes a redundant strategy different is:
•
A redundant control engine
•
Persistent/redundant variables
•
One or more transactional charts, which use sync blocks to organize logic into transactions
In order to create a strategy to run on redundant controllers, you must first configure
persistent/redundant variables that you want to be replicated to the backup controller. Then you
create transactional charts, using sync blocks to indicate where in the logic you want the
synchronizations to occur.
Creating a PAC Control strategy for controller redundancy includes the following tasks.
“Step 1. Enabling the PAC Control Redundancy Features” on page 33.
“Step 2. Adding a Redundant Control Engine to a PAC Control Strategy” on page 36.
“Step 3. Configuring Persistent/Redundant Data” on page 39.
“Step 4. Designing a Transactional Chart” on page 41.
Step 1. Enabling the PAC Control Redundancy Features
When redundancy is enabled for a strategy, the following features become available:
•
The Sync Block icon appears in the toolbar. If you do not see the sync block icon, click in
the logic area of a chart to make it appear. For information on using sync blocks in a
strategy, see Chapter 4: Creating a Strategy with Controller Redundancy.
Sync block tool
•
PAC Redundancy Manager can be accessed within PAC Control for control engines configured
for controller redundancy. You can also access PAC Redundancy Manager from the Start menu:
select StartProgramsOpto 22PAC Project SoftwarePAC Redundancy Manager. For
instructions on using Redundancy Manager, see “Step 2. Adding a Redundant Control Engine to
a PAC Control Strategy” on page 36 and sections in Chapter 3 and Chapter 5.
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You can select PAC Redundancy
Manager from the pop-up menu.
•
The Persistent/Redundant option becomes available on the Add/Edit Variable dialog box.
Redundant variables are persistent variables that are replicated to a backup controller when
one is available. For more information, see Chapter 4: Creating a Strategy with Controller
Redundancy.
Persistent/Redundant
variable option
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•
Controller Redundancy - Debug Options become available in a pop-up menu for control
engines configured for redundant controllers. For more information, see “Using Controller
Redundancy – Debug Options” on page 60.
To enable the redundancy features in PAC Control:
1. Start PAC Control by clicking the Start button and selecting ProgramsOpto 22PAC Project
PAC Control Pro.
The PAC Control main window opens.
2. Click the Open Strategy button
on the toolbar, or select FileOpen Strategy.
3. In the Open Strategy dialog box, navigate to the strategy you will use for the redundant system,
and then open it.
4. Select File > Strategy Options, and then click the Redundancy tab.
5. Click the text highlighted in blue: “Enable controller redundancy support.”
When enabled, the Strategy Options dialog box looks like this:
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6. Click the Download tab.
7. In the Flash Memory section, make sure that both of these options are checked:
– Save strategy to flash memory after download
– Set autorun flag after download
8. Click OK.
Step 2. Adding a Redundant Control Engine to a PAC Control
Strategy
In order to access PAC Redundancy Manager from within PAC Control, or to create a strategy to
control a system with controller redundancy, you must first add a control engine to your strategy
that is configured for redundant controllers. You can either add to your strategy the control engine
you created in Chapter 3 (see “Creating a Control Engine for Controller Redundancy” on page 24), or
you can configure a control engine from within PAC Control.
Adding an Existing Redundant Control Engine
If you’ve already created a control engine for redundancy (page 24), add it to your strategy using
these steps. If you need to modify a control engine for redundant controllers, see the next section,
“Configuring an Existing Control Engine for Redundancy” on page 37.
1. Make sure you have connected the hardware and configured a redundant system as described
in the two previous chapters.
2. With a strategy open in PAC Control in Configure mode or Online mode, choose Configure
Control Engine.
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In the Configure Control Engines dialog box, the redundant control engine’s name appears in
the list.
Active engine
List of control engines
3. Check to make sure the correct control engine appears in the Active Engine field. If not,
highlight the one you want and click Set Active.
Only one control engine can be active at any time. If only one control engine is listed, it
automatically becomes the Active Engine.
Configuring an Existing Control Engine for Redundancy
Use the following procedure to configure an existing control engine with redundant controllers.
1. Start PAC Control and open your strategy in Configure mode or Online mode.
Define a control engine for your strategy as described in form 1700, the PAC Control User’s Guide.
2. Double-click your control engine on the Strategy Tree to open the Configure Control Engines
dialog box.
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3. Click Modify.
The Select Control Engine dialog box appears.
This dialog box lists all the control engines configured on your system, whether or not they are
associated with your strategy.
4. Highlight the control engine’s name and then click Modify.
The Control Engine Configuration dialog box appears.
5. Under System Type, select Redundant Controllers.
New Settings options appear.
6. Using the IP addresses you created earlier, enter the IP address for Controller 1, Controller 2, and
the Arbiter, then click OK.
NOTE: These are the addresses you configured previously for the controllers and arbiter. See “Assigning
a Primary IP Address to ENET 1 on each Controller” on page 17 and “Assigning an IP Address to the
Arbiter” on page 21.
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The completed dialog box will look something like this:
7. For Controller Port, Software Retries, and Software Timeout, use the default settings:
Controller Port: 22001
Software Retries: 0
Software Timeout: 5000 msec
8. Click OK.
9. In the Select Control Engine dialog box, make sure the correct control engine is highlighted,
and then click OK.
10. Click OK again to close the Configure Control Engines dialog box.
Step 3. Configuring Persistent/Redundant Data
Redundant variables (labeled as Persistent/Redundant in PAC Control) are persistent variables that
are replicated to an available backup controller whenever synchronization occurs. For optimal
performance of your redundant system, best practice is to always use transactional charts. Also, keep
in mind to use redundant variables only as necessary. Because each additional redundant variable
must be synchronized, too many can increase system overhead and slow down the system.
All redundant variables (as well as I/O changes) are synchronized no matter where the change is
initiated, either in a running chart or when using Debug Mode in PAC Control. I/O changes include
setting outputs, starting pulsing, and so on.
When a redundant variable that resides in a transactional chart is changed, the value on that
controller changes immediately, but it is not synchronized until the next sync block is encountered.
When a redundant variable resides in a non-transactional chart (a chart without sync blocks), the
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variable is synchronized immediately after it is changed, and this can cause your system to slow
down.
To create a persistent/redundant variable, see “Configuring Redundant Variables” on page 40.
Persistent/Redundant Variables
Most variables can be persistent/redundant. However, pointer variables, pointer tables, and timers
can be redundant but not persistent. Normally, variables are set to an initial value (which you specify
during configuration) either whenever the strategy is run or whenever it is downloaded.
Persistent/redundant variables, however, are initialized only when the strategy is first downloaded.
Persistent variables are initialized with zero until set for the first time, after which the value does not
change unless the strategy or other client changes it. The variable’s value is saved in the controller’s
memory; it does not change when the strategy is run, stopped, or started, and it does not change if
the strategy is changed and downloaded again.
A persistent/redundant variable’s value remains the same until one of the following events occurs:
•
The value is changed with PAC Control Debugger or other client.
•
A strategy with a different name is downloaded.
•
The RAM memory on the controller is cleared.
•
New firmware is downloaded to the controller.
•
The persistent/redundant object is changed as follows:
– A persistent/redundant table's length (integer, 64-bit integer, float, and string) is modified.
– A persistent/redundant string variable's length is modified.
– A persistent/redundant string table element's string length is modified.
– A persistent/redundant variable's type is changed. For example, a persistent/redundant
float variable is deleted and a new persistent/redundant integer variable is created with the
same name.
•
The strategy writes a new value to the variable.
Configuring Redundant Variables
To add a redundant variable:
NOTE: These are basic instructions only. For more information on configuring variables, see Chapter 9:
Using Variables and Commands in form 1700, the PAC Control User’s Guide.
1. Make sure that redundancy is enabled for the strategy. See page 33.
2. With the strategy or subroutine open in Configure mode, choose ConfigureVariables.
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The Configure Variables dialog box opens.
3. In the Type drop-down list, choose the type of variable you want to configure.
4. If you are adding the variable to a subroutine, select Subroutine in the Scope drop-down list.
5. Click Add.
The Add Variable dialog box appears.
Persistent/Redundant
variable option
6. Name the variable, select the type, and under Initialization, select Persistent/Redundant.
7. Click OK.
The Add Variable dialog box closes and the new variable appears in the Configure Variables
dialog box.
Step 4. Designing a Transactional Chart
NOTE: Before you begin, make sure to enable the redundancy features in PAC Control. (See page 33.)
This section describes the basics of how to design a transactional chart, a special PAC Control chart
that you must use if your strategy is used to support persistent/redundant data with redundant
controllers. You create a transactional chart simply by adding sync blocks at strategic places in a PAC
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Control chart’s logic. A transactional chart is usually sequential; it starts at one block and proceeds
sequentially through command blocks to the end using variables, inputs, and outputs.
Sync block
A transactional chart’s logic is organized as a series of transactions, a term borrowed from the
transactional database world. For our purposes, a transaction is a collection of redundant operations
that are logged and deferred until a sync block is encountered, at which point the data generated by
a transactional chart is synchronized in both the active and backup controllers. Each transaction
starts with the first write of a persistent/redundant variable or I/O, and it ends with a sync block.
This block reads the tray sensor.
It does not start a transaction.
This block writes to the conveyor I/O
point, so the transaction starts here.
The transaction ends
with the next sync block.
If the active controller fails, the sync block also indicates to the backup controller what state the
chart is in (running/stopped/paused) and where in the logic to begin. In this case, the backup
controller takes over as the active controller.
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The chart restarts on the new active controller beginning with the closest sync block previous to the
failure point.
2) Chart starts here on
the backup controller
1) Active controller
fails here
Active
Backup
Transaction Example
In this example of a transactional chart, a cookie baking process is implemented on redundant
controllers using sequential programming. As shown in the illustration, the highlighted transaction
starts when the conveyor is stopped. It continues by turning on the oven and the bake timer. The
transaction ends at the next sync block.
Short delay
Transaction
starts
Transaction ends
Sync block
Using a redundant bake timer variable maintains the proper baking time. If a long delay were used
instead to control bake time, a restart to the previous sync block would result in the delay occurring
twice and the cookies would burn. Short delays can be used to facilitate the efficient execution of a
strategy. However, longer delays should not be used in a transactional chart.
Design Considerations and Chart Constraints
Consider the following guidelines when designing a redundant control strategy:
•
Use persistent/redundant variables only as necessary. Because each additional
persistent/redundant variable must be synchronized, too many persistent/redundant variables
can increase system overhead and slow down the system.
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•
Construct logic using sequential programming. See “Transaction Example” on page 43.
•
Do not use long delays.
When developing a transactional chart, keep the following constraints in mind:
•
Counters cannot be cleared.
•
Latches are unavailable (but a counter can be used in place of a latch by storing and comparing
count values).
•
Min/Max clearing is not supported, so Min/Max functionality is not useful.
•
The following commands are not supported in redundant strategies:
– Call Chart
– Clear All Latches
– Clear Counter
– Clear Off-Latch
– Clear On-Latch
– Continue Calling Chart
– Get & Clear Analog Maximum Value
– Get & Clear Analog Minimum Value
– Get & Clear Counter
– Get & Clear Off-Latch
– Get & Clear On-Latch
– Get Off-Latch
– Get On-Latch
– IVAL Set Off-Latch
– IVAL Set On-Latch
•
Subroutines may not contain sync blocks. However, a subroutine may perform operations on
redundant objects.
•
Called charts are not supported. (Call Chart is not supported, but Start Chart is.)
•
You cannot do background downloads. However, PAC Redundancy Manager allows you to
download to the non-active controller and then quickly switch over to it.
Using Reads and Timers
Reads can occur at any time. Reading an analog channel, for example, occurs the moment the
command is executed in the chart. The same is true when reading any kind of variable or change
to I/O.
Timers are similar to redundant variables in that if you start a timer, it does not start in the other
controller until a sync block is encountered; starting a timer is a write operation. Once started and
synced, the timer is activated in both controllers. Each controller can read from that timer without
requiring a sync block or synchronization to occur. However, stopping a timer requires a sync block
to be encountered to stop the timer on both controllers.
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What Causes Synchronization to Occur
A synchronize operation is performed whenever a sync block is encountered in a transactional chart.
A sync operation is also performed for the following reasons:
•
Changes occur in non-transactional charts (without sync blocks) to persistent/redundant
variables and I/O.
NOTE: Changing redundant variables and I/O in non-transactional charts can cause your system to
slow down significantly because without sync block, the controllers are synchronized each time a
persistent/redundant variable changes. Therefore, in charts with persistent/redundant variables,
whenever possible use sync blocks to control when the controllers are synchronized.
•
An operator changes a value for a persistent/redundant variable in PAC Control Debug mode or
in PAC Display Runtime. Only the changed persistent/redundant variable is synchronized. In
Runtime, if an operator changes a tag that is linked to a persistent/redundant variable, the
changed variable is synchronized immediately.
Adding a Sync Block
A sync block is added to a chart in the same way that other PAC Control blocks are added (an action
or condition block, for example). For more information on adding a block and using it in a chart’s
logic, see form 1700, the PAC Control User’s Guide.
1. Make sure that redundancy is enabled for the strategy. See “Step 1. Enabling the PAC Control
Redundancy Features” on page 33.
2. With the chart open and the strategy in Configure or Online mode, click the Sync block tool.
Sync block tool
3. Move the mouse into the window, and notice an outline representing the block.
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4. Click where you want to place the block.
The new block appears.
5. Click in another location to place other blocks of the same type.
6. When you have finished using the tool, click the right mouse button, click another tool in the
toolbar, or press ESC.
To use sync blocks in a chart’s logic, you’ll need to name the block, and connect it to other blocks in
the chart. You can also change the size of the block, its color, and the font. For more information, see
form 1700, the PAC Control User’s Guide.
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5: 5: System MaintenanceChapter 5
5: System Maintenance
This chapter describes how to change an IP address on a controller or arbiter, load new firmware,
reset the arbiter, use the PAC Redundancy Manager advanced features, and various other system
maintenance tasks.
In This Chapter
Checking System Status ............................................................................47
Changing an IP Address on a Device...................................................52
Installing New Firmware............................................................................53
Managing Memory......................................................................................56
Using Advanced Functions ......................................................................58
Using Controller Redundancy – Debug Options ...........................60
Arbiter Status LEDs and Blink Codes ....................................................61
Resetting the Arbiter...................................................................................62
Checking System Status
When you have completed your strategy and it is running on the controller, you can check the status
of the arbiter and both of the controllers using System Overview in PAC Redundancy Manager.
1. Make sure you have a fully configured redundant system, and your strategy is downloaded and
running on your redundant system.
For more information about downloading and running a strategy, see form 1700, the PAC
Control User’s Guide.
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2. In PAC Redundancy Manager, under Tasks & Tools > System Management, click System
Overview.
The System Overview screen displays basic device information, such as IP address, type of
device, and the strategy running on the controllers. It also displays status messages which you
can use to troubleshoot your system. See the sections below, “Redundant System Status
Messages” and “Redundant System State Machine.”
Redundant System Status Messages
The System Overview screen in PAC Redundancy Manager displays status messages about the state
of the arbiter and the controllers. You can use this information to address problems with your
system. For additional help, also see the next section, “Redundant System State Machine.”
Status message
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Status messages for the arbiter include Connected, Trying to connect, and Not connected.
Status messages for the controllers include:
Message
Description
Active
The controller has a strategy and is able to run it. The strategy may or may
not be running at the moment.
Active (I/O Impaired)
The controller has a strategy and is able to run it. However, one or more
I/O units failed to respond to the controller's communication request within
the allowed time. You should verify that all I/O units are online. If that
doesn't resolve the issue, you can increase the arbiter's loop time by setting its value in the memory map (arbiter MMP address 0xF8000104). The
default value is 50 milliseconds (00000032 hex) and the maximum value is
250 milliseconds (000000FA hex).
Cold Start
The controller is changing to active. This is usually a very short state.
Failed
The controller is not responding to the arbiter. It may be off, or disconnected, or have firmware or hardware issues.
Failed (Possibly Active)
The controller is not responding to the arbiter. Its last known state was
Active, and it may still be running its strategy.
Failover Start
The backup is changing to active and starting in the state of the previously
active controller.
Maintenance
Used for certain operations, such as download a strategy or installing firmware.
Non-Qualified Backup
The controller is attempting to become qualified (copying firmware, strategy, and chart state from the active controller). This state occurs frequently, and it can take a while to complete everything. This message may
also indicate that the backup controller cannot communicate with the I/O.
Online (Candidate)
Controller has a strategy and may become active. Usually a very short
state.
Online (non-candidate)
The controller has no strategy.
Powerup
A controller enters this state when it is first turned on.
Qualified Backup (Connected)
The controller is a qualified backup (ready to become active).
Qualified Backup (Disconnected)
The controller is a qualified backup but is not currently connected to the
active controller.
Update Complete
Used when a controller is coming out of Maintenance mode with a strategy
loaded and is attempting to become active. This is usually a very short
state.
Using the Memory Map to Read Status Messages
To see the status of a redundant controller in PAC Display, use the PAC Control command
Read Number from I/O Unit Memory Map with the memory map address 0xF8001000. By frequently
reading the value in an I/O unit’s memory map and putting it into a variable, you can display the
status in PAC Display.
The value returned indicates the redundant controller’s status, as follows:
State
Powerup
Value (Decimal)
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State
Value (Decimal)
Maintenance
2
Online: Non-Candidate
3
Backup: Non-Qualified
4
Online: Candidate
5
Update Complete
6
Backup: Qualified Connected
7
Cold Start
8
Failover Start
9
Active
10
Backup: Qualified Disconnected
11
Using the Memory Map to Enter and Exit Maintenance Mode
To exit or enter maintenance mode programmatically in a PAC Control strategy, use the PAC Control
command Write Number to I/O Unit Memory Map with the memory map address 0xF8001000. Use
either a hexadecimal or ASCII value from the following table for the desired command.
Command
Hexadecimal Value
ASCII Value
Enter Maintenance
0x4D
M
Exit Maintenance (become active)
0x4241
BA
Exit Maintenance (reset)
0x52
R
Entering Maintenance Mode on Boot
The memory map address 0xF8001004 reads/writes the Enter Maintenance Mode flag. Use the PAC
Control command Read Number from I/O Unit Memory Map to read this memory location. If this
flag is TRUE, on boot the controller will enter maintenance mode.
To set the Enter Maintenance Mode flag to TRUE, write the value 0x4D41494E (hex) or MAIN (ASCII)
to memory map address 0xF8001004. The controller will enter maintenance mode on boot. If any
other value is used, it won’t enter maintenance mode.
Redundant System State Machine
You can use the information below to better understand the PAC Redundancy Manager status
messages and the sequence in which some system states occur. Messages appear in PAC
Redundancy for each of the redundant controllers. For definitions of the status messages, see the
previous section, “Redundant System Status Messages.”
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Power cycle
safety zone*
* When in this zone, the arbiter assumes that the controller may be active. If the arbiter loses communications
with a (possibly) active controller, it must turn off power to that controller before telling the backup to become
active. Otherwise you might have two simultaneous active controllers. Because turning off power to a device
that is doing a flash write may cause corruption of data in flash memory, writes to flash memory (such as
configuration writes, strategy updates, and firmware updates) are disabled.
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Changing an IP Address on a Device
NOTE: This section details how to change an IP address on a system device, either a controller or the arbiter.
To assign an IP address for the first time, see “Assigning an IP Address to the Arbiter” on page 21.
1. In PAC Redundancy Manager, under General Tools on the main window, click Change IP
Address.
The Change IP Address dialog box opens.
2. In the Current IP Address text box, enter the current IP address for the device.
3. Click Read Current Settings to see the Subnet Mask, Gateway, and DNS Address.
4. Enter a new IP address or other setting as needed, and then click Apply Settings.
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5. Note the progress as the device is reset and tested.
After you confirm the change, a message appears stating that the change was successful and
that the device will restart. Restarting may take 10 to 20 seconds to complete. When the STAT
LED shows solid green or solid orange when viewed from the top, the device is ready for use
with its new address. Green means a strategy is running; orange means no strategy is running.
Remember to write the IP address on the sticker or white area on the device.
Installing New Firmware
Each PAC controller and SNAP-PAC-SRA arbiter contains firmware, which is similar to an operating
system. In the unlikely event that the firmware becomes damaged, or if a new version of the
firmware is released, you can load new firmware to the controllers or arbiter using the PAC
Redundancy Manager.
Installing Firmware to the Controllers
There are two different ways in PAC Redundancy Manager to install firmware to the controllers. The
default and recommended method, Running System method, updates the firmware on a running
system with as little disruption as possible. The other method, Controller, should not be used on a
connected redundant system.
Using the Running System Method
1. Under Arbiter Management on the PAC Redundancy Manager, click Install Firmware.
The Install Firmware window appears.
2. Check to make sure that Running System is selected in the top pane.
3. Under System Update, specify a strategy to be downloaded, in the form of a Controller
Download File (CDF) in PAC Control.
The CDF is required because a strategy is downloaded to the controller during the updating
process. To generate a CDF file, open the strategy in PAC Control and select Compile > Compile
Control Engine Download File. For more information, see form 1700, the PAC Control User’s
Guide.
4. Under Firmware, browse to the firmware location and select the new firmware file.
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5. Scroll down to the bottom of the screen and click Update Firmware.
Progress of the upload appears at the bottom of the window. If an error occurs, notice the
onscreen message.
Using the Controller Method
CAUTION: Do not use this method of installing firmware on a fully connected redundant system. It may be
overwritten by the normal backup qualification process.
1. Turn off either the arbiter or the other controller.
2. Under Arbiter Management on the PAC Redundancy Manager, click Install Firmware.
3. On the Install Firmware window, select Controller.
4. Under Firmware, browse to the firmware location and select the new firmware file.
5. Scroll down to the bottom of the screen and click Update Firmware.
Progress of the upload appears at the bottom of the window. If an error occurs, notice the
on-screen message.
Installing Firmware to the Arbiter
NOTE: It is OK to install firmware to the arbiter while the system is running.
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1. Under Arbiter Management on the PAC Redundancy Manager, click Install Firmware.
The Install Firmware window appears.
2. Select Arbiter in the top pane.
3. Under Arbiter Device, select Selected Arbiter.
4. Under Firmware, browse to the firmware location and select the new firmware file.
5. Scroll down to the bottom of the screen and click Update Firmware.
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Progress of the upload appears at the bottom of the window. If an error occurs, notice the
onscreen message.
Managing Memory
Controllers have various settings that can be configured, usually with PAC Manager, that are stored
in RAM. You can use PAC Redundancy Manager to manage a redundant controller's memory, such
as storing and erasing strategies and configurations in flash memory or on a microSD card (for SNAP
PAC controllers manufactured in November 2008 and later that have a microSD card slot in the top
of the controller’s case).
Saving to flash protects a configuration from being lost if the controller is turned off. When you save
to flash, the new configuration overwrites any configuration already in the flash memory.
CAUTION: Updating a redundant controller's memory can disrupt a running system. During the update,
the controller must be placed into Maintenance mode, during which time it cannot be the Active controller.
If the controller is currently Active, the strategy will be stopped. If there is a qualified Backup controller, it will
become Active.
The following options are available in PAC Redundancy Manager:
Strategy Memory. The following commands are available:
•
Store Strategy to Flash: Saves the strategy to flash memory. Only one strategy at a time can be
stored in flash memory.
•
Erase Strategy from Flash: Erases the strategy currently stored in flash memory.
•
Erase Strategy from RAM: Erases the strategy from RAM.
Configuration Flash Memory. The following commands are available:
•
Store Configuration to Flash: Saves the configuration to flash memory.
•
Erase Configuration from Flash: Erases the configuration stored in flash memory, which
includes:
– Clears error information in the status area (error code, transaction label, source address,
error address).
– Clears gains and offsets, counters (which are also deactivated),
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– latches, min/max data.
– Turns off digital outputs.
– Sets analog outputs to zero scale (0 counts).
•
Reset Configuration to Defaults and Reset: Erases the configuration from flash memory (see
above), restarts the controller, and resets points to defaults.
microSD Card. The following commands are available:
•
Store Configuration to microSD card
•
Erase Configuration from microSD card
•
Erase Firmware from microSD card
•
Erase Strategy microSD card
•
Copy microSD card to Flash
IMPORTANT: Before using the microSD card in your controller, make sure to read the section “Using the
MicroSD Card” in chapter 3 of form 1592, the SNAP PAC S-Series User’s Guide.
To manage a strategy or configuration in memory:
1. In PAC Redundancy Manager, under Tasks & Tools > Controller Management, click Manage
Memory.
2. Under Controller, select the controller to manage.
3. Under Memory Commands, select a command.
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USING ADVANCED FUNCTIONS
4. Scroll down to the bottom of the screen, and click the button that displays the command you
selected, such as Store Strategy to Flash.
Progress is displayed at the bottom of the screen.
Using Advanced Functions
CAUTION: The advanced functions are for diagnostic and troubleshooting purposes. Misuse of these
features can have unintended consequences. If you are unsure about how to use these features, please
contact Opto 22 Product Support. See “Product Support” on page 5.
A number of powerful advanced functions are provided which you can use to:
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•
Troubleshoot the system
•
Use Maintenance mode to perform an operation not provided in PAC Redundancy Manager
•
Have the arbiter reset a controller
•
Directly control the power switch
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To use the advanced functions:
1. Under Tasks & Tools > System Management, click System Overview.
2. Scroll down to the bottom of the screen and select Show Advanced Functions.
Two sets of advanced function commands appear, one for each controller:
A
B
C
D
E
F
G
H
3. Using the Advanced Functions window for the controller you want to manage, select one of
the following options.
A Enter Maintenance: Stops any running strategy.
NOTE: See also, “Using the Memory Map to Enter and Exit Maintenance Mode” on page 50.
B Exit Maintenance to Powerup state: Exits maintenance mode when there is no strategy
loaded. For more information on maintenance mode, see D below.
C Exit Maintenance and become Active: Exits maintenance mode when there is a strategy
loaded. For more information on maintenance mode, see D below.
D Enter Maintenance mode when booting: Causes the controller to enter Maintenance
mode when the controller first boots. This is used during firmware uploads. It ensures that
no backup qualification takes place. By going into maintenance mode, the controller sits
idle and does not become active or backup; no firmware or strategy is automatically copied
to it.
E Safe Reset: Performed only if the arbiter determines that system integrity can be
maintained.
F Force Reset: Forces the arbiter to reset the controller.
G Hard Reset: Forces the arbiter to cycle the controller’s power.
H Redundant Power Switch State: Controls the redundant power switch. You can switch it
on or off.
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USING CONTROLLER REDUNDANCY – DEBUG OPTIONS
Using Controller Redundancy – Debug Options
With a control engine associated with your strategy and configured for redundant controllers (see
“Step 2. Adding a Redundant Control Engine to a PAC Control Strategy” on page 36), PAC Control will
automatically select which controller to use for downloading and debugging. While in this
automatic mode, PAC Control downloads to the non-active controller whenever possible so that the
active controller can keep running during the download.
In order to handle a variety of download and debug scenarios, PAC Control also provides other
debug options.
To access the debug options:
1. Make sure you have turned on the redundancy options in PAC Control. For more information,
see “Step 1. Enabling the PAC Control Redundancy Features” on page 33.
2. Right-click the control engine you configured previously for controller redundancy, and select
Controller Redundancy – Debug Options to see the available options.
3. Choose one of the following settings.
Automatic Controller Selection: This setting is selected by default because it is the least
disruptive to your system. It should be used when you have connected and configured an
arbiter and at least one controller. With this setting PAC Control will select which controller to
use for downloading and debugging. If possible, it downloads to the non-active controller, so
that the active controller can keep running during the download.
Use Controller 1 (or 2) with Arbiter: Use this option when there is an arbiter connected and
you want to download to or debug a specific controller during development or
troubleshooting. Possible scenarios for using this option include demonstrating the control
system, diagnosing a problem, network sniffing, and so on. When using this option, the arbiter
manages the other controller by turning it off during the download.
Use Controller 1 (or 2) without Arbiter: You can use this option when there is there is no
arbiter connected and you want to download to or debug a specific controller during
development or troubleshooting. In this case, you must make sure that the other controller is
turned off. One possible use of this option is in a deployed system where the arbiter is not
working.
CAUTION: In order to avoid having two active controllers at the same time or unpredictable behavior
from your system, make sure that the other controller is off.
Debug Backup Controller: Use this option only if you want to debug the current qualified
backup controller. No downloads are allowed.
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Arbiter Status LEDs and Blink Codes
The following diagram shows the location of the arbiter’s status LEDs. See below for descriptions of
the LEDs and the system blink codes.
Serial activity
not used
not used
Ethernet
activity
Controller 2 status
System status
Controller 1 status
not used
Arbiter status
Communication Status LEDs
LED
Indicates
LNK
Link established with Ethernet network
ACT
Ethernet network activity
TX
Outgoing serial activity
RX
Incoming serial activity
System Status LEDs
LED
Indicates
ARB
Arbiter Status
Off = arbiter has failed or is not powered
Red = arbiter has failed
Orange = arbiter is starting
Green = arbiter is online
SYS
Controller Redundancy System Status
Red = no controller is active
Orange = one controller is active, with no qualified backup
Green = one controller is active, with a qualified backup
CTR1
Controller 1 Status
Red = failed
Orange-blinking = backup is qualified but cannot communicate
with one or more configured I/O units, or not qualified
Orange = backup qualified
Green-blinking = becoming active, or active but cannot communicate with one or more configured I/O units
Green = active nominal
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RESETTING THE ARBITER
LED
Indicates
CTR2
Controller 2 Status
Red = failed
Orange-blinking = backup qualified but cannot communicate with
one or more configured I/O units, or not qualified
Orange = backup qualified
Green-blinking = becoming active, or active but cannot communicate with one or more configured I/O units
Green = active nominal
Resetting the Arbiter
1. Carefully insert a straightened paperclip or stiff wire into the small hole on the side of the
arbiter.
Reset button
2. Press and hold down the RESET button as described below.
To perform this kind of reset...
Simple restart
...do this
Press and immediately release
the RESET button.
Result
The arbiter restarts.
OR
Turn off power to the arbiter and
then turn it on again.
OR
Use PAC Manager to send the
arbiter the “Restart from Powerup”
command.
Restore factory default
settings
Press and hold the RESET button
for 1 or 2 seconds until the STAT
LED turns solid green, and then
immediately release the button.
Don’t hold it down too long.
•
•
The arbiter restarts.
IP address is reset to 0.0.0.0 and
subnet mask to 255.255.255.0.
CAUTION: Do not hold down the RESET button too long. If you hold it down longer than five seconds, the
arbiter will enter hardware test mode, which is indicated by the STAT LED blinking orange, rapidly and
continuously. Hardware test mode erases all files in RAM and flash memory and resets the IP address. If
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your arbiter restarts in hardware test mode, cycle power; the result will be the same as restoring factory
default settings (see table above).
If you hold down the RESET button less than five seconds but longer than the time needed to restore the
default settings, the arbiter will restart in failsafe 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 arbiter restarts in failsafe bootloader
mode, cycle power; the result will be same as the simple restart described above.
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RESETTING THE ARBITER
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