Page 3 - Preface; Content of this Manual
iii GFK-0827 Preface This manual is a reference to the hardware components, configuration and operation ofthe Hot Standby CPU Redundancy system for the Series 90 t -70 Programmable Logic Controller. This redundancy system is one of several redundancy alternatives that maybe incorporated into a Serie...
Page 4 - We Welcome Your Comments and Suggestions
Preface iv Hot Standby CPU Redundancy User ’s Manual - December 1993 GFK-0827 Series 90-70 PLC Reference Manual (GFK-0265). Reference manual which describes operation, fault handling, and Logicmaster 90-70 programming instructions for theSeries 90-70 PLC. Series 90-70 Remote I/O Scanner User’s Manua...
Page 5 - Contents; Chapter 1
Contents v GFK–0827 Series 90–70 Hot Standby CPU Redundancy User ’s Guide – December 1993 Chapter 1 Introduction 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hot Standby CPU Redundancy Product 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
Page 6 - Chapter 2
Contents vi GFK–0827 Series 90–70 Hot Standby CPU Redundancy User ’s Guide – December 1993 Chapter 2 System Components 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Redundancy CPU 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
Page 7 - Chapter 3
Contents vii GFK–0827 Series 90–70 Hot Standby CPU Redundancy User ’s Guide – December 1993 Chapter 3 Configuration 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Configuring a Hot Standby CPU Redundancy System 27 . . . . . . . . . . . . . . . . . Redund...
Page 8 - Chapter 4
Contents viii GFK–0827 Series 90–70 Hot Standby CPU Redundancy User ’s Guide – December 1993 Chapter 4 Operation 55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Section 1: System Operation 55 . . . . . . . . . . . . . . . . . . . . . . . . . . . ....
Page 9 - Section 2: Fault Detection and Control Actions
Contents ix GFK–0827 Series 90–70 Hot Standby CPU Redundancy User ’s Guide – December 1993 Section 2: Fault Detection and Control Actions 72 . . . . . . . . . . . . . . . Fault Detection 72 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fault Ca...
Page 12 - Note; Hot Standby CPU Redundancy Product
1 section level 1 1figure bi level 1 table_big level 1 restart lowapp ARestart oddapp: ARestarts for autonumbers that do not restart ineach chapter. figure bi level 1, reset table_big level 1, reset chap_big level 1, reset1Lowapp Alwbox restart evenap:A1app_big level 1, resetA figure_ap level 1, res...
Page 14 - Features of the Hot Standby CPU Redundancy Product; Benefits of the Hot Standby CPU Redundancy Product
1 3 GFK-0827 Chapter 1 Introduction Features of the Hot Standby CPU Redundancy Product H Bumpless switching h Synchronized CPUs h 20 millisecond scan extension (nominal). This figure is variable, depending onamount of data transferred. h One scan switching (in most cases) h Configurable backup data ...
Page 15 - I/O Systems for Hot Standby CPU Redundancy Systems
1 4 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 I/O Systems for Hot Standby CPU Redundancy Systems Both Series 90-70 Local I/O and Genius I/O systems can be present in a Hot StandbyCPU Redundancy control system. The two units are not required to have matching I/Osy...
Page 16 - Hot Standby CPU Redundancy System; Control Strategy; Basic Hot Standby Operation
1 5 GFK-0827 Chapter 1 Introduction Y Y C BT M RC M G BC 31 PRIMARY UNIT SECONDARY UNIT 30 B L OC K B L OC K SCANNER REMOTE DROP I O I O I O I O I O I O PS I O I O PS PS BT M G BC B L OC K I O I O I O I O I O I O I O I O PS P U C P U B R M RACK 0 RACK 1 RACK 0 I O I O I O I O I O I O I O I O PS RACK...
Page 18 - Redundancy CPU Module
1 7 GFK-0827 Chapter 1 Introduction Redundancy CPU Module The same model of CPU must be installed in both the Primary and Secondary PLCs.This CPU, which is the only CPU that currently supports synchronized Hot StandbyCPU redundancy, is the CPU 780 (catalog number IC697CPU780). This CPU is similar to...
Page 19 - Bumpless Switching
1 8 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 the two CPUs and provides the communications path for the transfer of I/O databetween the two units. An RCM must be configured in both the Primary PLC and theSecondary PLC. The RCM must reside in the CPU rack (rack 0)...
Page 20 - Configurable Backup Data Size
1 9 GFK-0827 Chapter 1 Introduction If the switch occurs due to a controlled condition such as toggling the unit selectionswitch on the Redundancy Communications Module or forcing a switch in the user logicprogram with a SVC_REQ, or because of a fault detected by the PLC CPU, then theswitch-over wil...
Page 21 - Programming Considerations
1 10 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Programming Considerations There are several features in the operation of the Redundancy CPU which are notsupported or are different then operation of other CPUs. These features are listed belowand are described in d...
Page 22 - Definition of Terms
1 11 GFK-0827 Chapter 1 Introduction The Primary Unit and the Secondary Unit must be configured separately. That is, theprogramming device should be connected directly to either the Primary or theSecondary Unit to configure that unit. When you have completed configuring that unit,disconnect the prog...
Page 23 - Commonly Used Acronyms
1 12 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Commonly Used Acronyms A list of acronyms used in this manual are defined for your convenience in the followingtable. Acronym Definition BRM Bus Receiver Module BSM Bus Switching Module BTM Bus Transmitter Module CPU...
Page 24 - Redundancy CPU
2 section level 1 1figure bi level 1 table_big level 1 13 GFK-0827 Chapter 2 System Components This chapter describes the hardware components for a Hot Standby CPU Redundancysystem. It describes the modules required for the system and provides catalog numbersof the components. For detailed installat...
Page 25 - Figure 3. CPU 780 Locations in a Hot Standby CPU Redundancy System; Table 1. Capacities for Redundancy CPU, IC697CPU780; CPU Architecture; Watchdog Timer
2 14 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 C P U C P U BTM RCM GBC 31 PRIMARY UNIT SECONDARY UNIT 30 PS PS BTM RCM GBC Genius Bus CPU 780 Redundancy Communications Link Redundancy Communications Link a47002 Figure 3. CPU 780 Locations in a Hot Standby CPU Red...
Page 26 - CPU Features
2 15 GFK-0827 Chapter 2 System Components timer is 10 milliseconds to 1000 milliseconds. The default value for the watchdog timer is200 milliseconds. The watchdog timer resets at the beginning of each sweep. The failwait time is included in the watchdog check. The watchdog timer should be set to all...
Page 27 - CPU Mode Switch; Table 2. Valid Operating Mode Selection; Run/Outputs Disabled; NOTE
2 16 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 CPU Mode Switch A three-position toggle switch is mounted near the top of the CPU board. This switchselects one of three operating modes for the CPU: RUN/ENABLED, RUN/DISABLED, orSTOP. Although the mode of operation ...
Page 28 - Memor y Protect Keyswitch; OK; Batter y Connectors
2 17 GFK-0827 Chapter 2 System Components Memor y Protect Keyswitch The Memory Protect keyswitch is located at the top of the module and has twopositions: ON and OFF. This keyswitch is used to manually lock program andconfiguration data. When the key is in the ”protected” (ON) position, program andc...
Page 29 - Serial Port Connector; Table 3. Expansion Memory Boards for CPU 780
2 18 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Serial Port Connector The 15-pin D-connector at the bottom of the module provides the connection to anRS-422/RS-485 serial port. Its port provides a serial connection to the Work StationInter face (WSI) board install...
Page 30 - Redundancy Communications Module; RCM Features; Figure 5. Redundancy Communications Module - IC697RCM711
2 19 GFK-0827 Chapter 2 System Components Redundancy Communications Module The Redundancy Communications Module (RCM), catalog number IC697RCM711, providesa communications path for sharing data between the two CPUs in the redundant system.In a synchronized system, I/O data is controlled by one unit ...
Page 31 - RCM System Status LEDS
2 20 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 C BT M RCM 31 PRIMARY UNIT SECONDARY UNIT 30 PS PS BT M RCM Redundancy Communications Link Redundancy Communications Link GBC GBC P U C PU ( RACK 0 ) ( RACK 0 ) a47005 Figure 6. Example of RCM Location in a Hot Stand...
Page 32 - LOCAL SYSTEM ACTIVE; Unit Selection Pushbutton
2 21 GFK-0827 Chapter 2 System Components LOCAL SYSTEM ACTIVE Indicates whether the local unit is the controlling (or active) unit in a redundancysystem. It is the responsibility of the local unit to set the state of this LED at least onceduring each sweep; if the local unit is unable to set (or fai...
Page 33 - Bus Transmitter Module; LED Status Indicators; Module OK
2 22 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Bus Transmitter Module A Bus Transmitter Module (BTM), catalog number IC697BEM713, is required in both thePrimary PLC CPU rack (rack 0) and the Secondary PLC CPU rack (rack 0) in a HotStandby CPU Redundancy system. T...
Page 34 - BTM Connectors; Bus Receiver Module
2 23 GFK-0827 Chapter 2 System Components BTM Connectors There are two connectors on the front of the BTM board. The top one provides a parallelconnection to a Work Station Interface (WSI) board installed in the programmer for theSeries 90-70 PLC. Serial connection to Workmaster II is through a prog...
Page 35 - I/O Bus Signal Termination; Board OK; BRM Connectors; Genius Bus Controller
2 24 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 I/O Bus Signal Termination The I/O bus signals must be terminated at the end of the bus. In a standard PLC systemthis is done by installing a resistor pack, located inside of a terminator plug (catalognumber IC697ACC...
Page 36 - Genius Bus Controller User Features
2 25 GFK-0827 Chapter 2 System Components The Hot Standby CPU Redundancy system uses a single Genius bus and requires one GBCmodule in the Primary PLC and one in the Secondary PLC; however there can be multipleGenius busses configured in this manner in a system. The GBCs in the Primary PLC areassign...
Page 37 - CH 1 OK; GBC Connectors; Racks
2 26 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 CH 1 OK The CH 1 OK LED is the middle LED. It operates identical to the Module OK LED in that itis ON after the board has successfully completed the power-up diagnostics and OFF if afailure has been detected during t...
Page 38 - Configuring a Hot Standby CPU Redundancy System
3 section level 1 1figure bi level 1 table_big level 1 27 GFK-0827 Chapter 3 Configuration This chapter describes how to configure a Series 90-70 PLC system for Hot Standby CPURedundancy. Several parameters in addition to the normally configured CPUparameters must be configured for the Redundancy CP...
Page 39 - Redundancy System Requirements; Basic Redundancy System Setup; For both Primary and Secondary CPUs, do the Following:; I/O System Configuration
3 28 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Redundancy System Requirements For a redundant CPU configuration using the Hot-Standby Redundancy scheme to bevalid, the following requirements must be true in both the Primary Unit and theSecondary Unit in the redun...
Page 40 - Screens for Fault Category Configuration
3 29 GFK-0827 Chapter 3 Configuration Screens for Fault Category Configuration A new Fault Category Configuration screen is displayed for the CPU 780. This newscreen has two columns of fault actions for the configurable fault groups/categories. Thefollowing sample screens show the Fault Category Con...
Page 41 - Handling Folders; Configuration with Logicmaster 90-70
3 30 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 The Fault Type is shown at the left. The first column under Fault Category (CFG) showswhich faults are FATAL and which faults are DIAGNOSTIC for this CPU, when it is theonly running CPU (i.e., stand-alone with no bac...
Page 42 - Configuration of a Redundancy CPU Module
3 31 GFK-0827 Chapter 3 Configuration cable connecting the PLC to the programmer should only be plugged and unpluggedwhen the programmer is powered up and offline. Avoid powering the parallel programmerup or down while connected to a running PLC. Configuration of a Redundancy CPU Module The redundan...
Page 44 - Redundant CPU Requirements
3 33 GFK-0827 Chapter 3 Configuration If the existing configuration does not require any modification to suit the redundantCPU configuration, the prompt ”REPLACE displayed module ? (Y/N)” will be displayedbeneath the softkey strip instead of the message box. If you answer ”Y”, page 1 of the detail s...
Page 45 - Redund Type; Background Window
3 34 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 3. In a redundant CPU system, RCMs cannot be configured in expansion racks. 4. Rack 7 cannot be seen nor edited. Redund Type This parameter specifies whether the CPU is configured as the primary controller or theseco...
Page 46 - Constant Window Sweep Mode
3 35 GFK-0827 Chapter 3 Configuration Constant Window Sweep Mode To change the Sweep Mode, move the cursor to the Sweep Mode field and press the Tabkey until the desired mode is displayed. Below is the detail screen (page 2) of aredundant CPU configured for CNST WND (constant window) sweep mode. Whe...
Page 47 - Ctrl Strgy
3 36 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 set for SIMPLEX mode. The parameters on this screen are Ctrl Strgy (Control Strategy),Fail Wait and SHARED I/O. Ctrl Strgy This parameter specifies which type of control strategy is selected for a redundancysystem. T...
Page 48 - Transfer Data Size
3 37 GFK-0827 Chapter 3 Configuration Table 4. Shared I/O Data Parameters I/O Parameter Description and Valid Entries %I Ref Adr Starting address for redundant %I data region. Range is %I00001...%I12288. The startingaddress is bit aligned. Default value is %I00001. %I LENGTH The bit length of the re...
Page 49 - Table 6. Transfer Data Size; Interrupts
3 38 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Note that the memory for the Shared I/O data that is stored at configuration must besubtracted from the amount of memory on the configured expansion memory module.The calculation for the size of the memory for Shared...
Page 50 - Configuring a CPU Expansion Memory Board
3 39 GFK-0827 Chapter 3 Configuration Configuring a CPU Expansion Memory Board To configure a CPU expansion memory board for the CPU 780, press the expbd softkey(F9) and then the memory softkey (F1). Position the cursor on the desired expansionmemor y board and press Enter to select that board. The ...
Page 51 - Configuration of a Redundancy Communications Module
3 40 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Configuration of a Redundancy Communications Module As described previously, one Redundancy Communications Module (the Local unit)must be configured in rack 0 (can be in slots 2 to 9). There must not be an empty slot...
Page 53 - Configuration of a Genius Bus Controller; Paired GBC Parameter
3 42 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Configuration of a Genius Bus Controller For this example, assume that a Genius Bus Controller has been configured in slot 3 ofrack 0. In a Hot Standby CPU Redundancy system, the Redundancy parameter(Redund Mode) of ...
Page 54 - Serial Bus Address
3 43 GFK-0827 Chapter 3 Configuration Serial Bus Address All redundant GBCs in the Primary CPU redundant system MUST be configured at SBA31. In the sample screen on the previous page, the rack level GBC is configured at SBA31. The Bus level GBC is automatically configured at SBA 30. All redundant GB...
Page 55 - Configuring a Primary Redundant PLC
3 44 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Configuring a Primary Redundant PLC The steps required for configuring a Primary Redundant PLC are described below. ThePrimary PLC and the Secondary PLC must be configured separately. An example of theconfiguration s...
Page 56 - Select the Redundancy CPU Module
3 45 GFK-0827 Chapter 3 Configuration Select the Redundancy CPU Module Move the cursor to the line for the Redundant CPU, IC697CPU 780, and press the Enterkey. A message is displayed beneath the softkey selection strip: ”REPLACE displayedmodule ? (Y/N)”. Press the Y key to replace the currently disp...
Page 57 - Select an Expansion Memory Board
3 46 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Press the PgDn key again to go to the next page of the CPU module. The default screenfor page 3 of the CPU detail screen appears as shown below: Select an Expansion Memory Board To configure a CPU expansion memory bo...
Page 58 - Configure the Redundant Communications Module
3 47 GFK-0827 Chapter 3 Configuration Press the Esc key twice to return to the rack level display, which now appears as shownbelow. Configure the Redundant Communications Module To configure an RCM in rack 0, slot 2, move the cursor to slot 2 and press the bemsoftkey (F3). The configuration screen f...
Page 59 - Configure a Genius Bus Controller
3 48 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Configure a Genius Bus Controller To configure a Genius Bus Controller module in rack 0, slot 3, position the cursor on slot3 and press the genius softkey (F2). To display the catalog list for the Genius BusControlle...
Page 61 - Configure Genius I/O Blocks
3 50 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 At this point, Press the Esc key and the bus screen will appear as shown below. Configure Genius I/O Blocks We will now configure a block for Bus Address 29. Move the cursor to block 29 andconfigure a bus block (Disc...
Page 62 - Configure the Bus Transmitter Module
3 51 GFK-0827 Chapter 3 Configuration When you have completed configuring Genius blocks, press the Esc key to go from theblock level display back to the bus level display. The bus display will now appear asshown below. Configure the Bus Transmitter Module Press the Esc key to return to the rack leve...
Page 63 - Configuring a Secondary Redundant PLC
3 52 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Configuring a Secondary Redundant PLC This section describes the steps for configuration of a Secondary PLC. The programmerfor Logicmaster 90-70 software must be connected to the Secondary PLC in order toconfigure th...
Page 64 - Change Redund Type
3 53 GFK-0827 Chapter 3 Configuration Position the cursor on rack 0, slot 1. Press the zoom softkey (F10) to zoom into the CPUmodule configured in slot 1. The detail screen (page 1) for the CPU module appears asshown below: Change Redund Type Change the Redund Type: parameter value from PRIMARY to S...
Page 66 - Section 5: System Operation; Power-Up Sequence of a Redundant CPU
4 section level 1 1figure bi level 1 table_big level 1 55 GFK-0827 Chapter 4 Operation This chapter discusses: H the normal operation of a Hot Standby CPU Redundancy PLC system; H what happens when a fault is detected and the system does not operate normally; H how to restore the system to normal op...
Page 68 - Resynchronization of the Redundant CPU
4 57 GFK-0827 Chapter 4 Operation Resynchronization of the Redundant CPU Whenever a CPU is attempting to get back in synchronization with the currently activeCPU, a resynchronization process will occur. This resynchronization process will occurany time a CPU performs a STOP to RUN mode transition. T...
Page 69 - Hot-Standby Redundancy Control Strategy
4 58 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Hot-Standby Redundancy Control Strategy In the Hot-Standby Redundancy Control Strategy, the primary CPU (designated by allGBCs addressed at bus address 31), is always the preferred CPU. The secondary CPU(designated b...
Page 70 - Synchronous Scan; Figure 8. Active and Backup Sweeps
4 59 GFK-0827 Chapter 4 Operation Synchronous Scan The figure below shows the sweep components for the active and the backup CPUs. Itshows the two communication points in the sweep. The first communication point isimmediately after the inputs are scanned. At this point in the sweep the newly readinp...
Page 71 - Data Transfer from Backup Unit to Active Unit
4 60 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 The transfer of the redundancy data during each sweep will be in blocks with each blockchecked for data integrity. The transferred data will be held in a temporary area by thebackup CPU until all data has been receiv...
Page 72 - Switching Control to Backup Unit
4 61 GFK-0827 Chapter 4 Operation through %P0008 on the backup unit will not change. %T0002 will be set whenever theoperation is successful and the data can be used. |REM_RDY %T00001|——| ↑ |—————————————————————————————————————————————————————————————————————( )— || _____ |REM_ACT | | %M00001 |——| |...
Page 73 - Role Switch SVCREQ
4 62 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 If the switch occurs due to a controlled condition such as toggling the RCM unit selectionswitch, forcing a switch in the user logic program, or because of a fault detected by thePLC CPU, then the switch-over will oc...
Page 74 - %S References for CPU Redundancy; Table 7. Definition for% S Reference for Redundancy Status
4 63 GFK-0827 Chapter 4 Operation %S References for CPU Redundancy There are seven special %S references which reflect the status of the Redundancy units:%S33 through %S39. The definition of these LEDs is shown in the following table. Table 7. Definition for% S Reference for Redundancy Status %S Bit...
Page 75 - Redundancy CPU Considerations; Features not Available with CPU 780
4 64 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Redundancy CPU Considerations The Redundancy CPU (CPU 780) has several restrictions and differences in operation ascompared to other Series 90-70 CPUs. The following features are not available with theCPU 780: H I/O ...
Page 76 - Differences in Operation for CPU 780; RUN Disabled Mode
4 65 GFK-0827 Chapter 4 Operation Differences in Operation for CPU 780 The following features operate differently with the CPU 780 than they do with otherSeries 90-70 CPUs: H RUN/DISABLED mode H Configuration of Fault Actions H STOP to RUN mode transition H Background Window Time (default is differe...
Page 79 - STOP to RUN Mode Transition
4 68 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Specific fault actions are described in Section 2 of this Chapter. However, you canconfigure whether or not a stand-alone CPU (after failure of the other CPU) will stop ifanother fault occurs. You can select the faul...
Page 81 - Miscellaneous Operation Information; Timed Contacts
4 70 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Where the Background Window Time is the time in milliseconds that you should set thebackground window timer. The other elements in the formula are described above inthe calculation for words per sweep. The constants ...
Page 82 - Genius Bus Controller Switching
4 71 GFK-0827 Chapter 4 Operation Genius Bus Controller Switching Genius Bus Controllers will stop sending outputs to blocks when no data has beenreceived from the PLC CPU for a period equal to two times the configured watchdogtimeout. If the CPU on the active unit becomes inoperative in an uncontro...
Page 83 - Section 6: Fault Detection and Control Actions; Fault Detection
4 72 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Section 6: Fault Detection and Control Actions This section describes how faults are handled in a Redundancy system. It discusses howfaults affect the operation of the Redundancy system, describes categories of fault...
Page 84 - Changing Fault Category Actions
4 73 GFK-0827 Chapter 4 Operation 3. faults and failures that are detected in the background. Faults and failures that are detected immediately are those that are identified within thecurrent sweep. These faults include I/O data corruption, single bit RAM failures, powersupply failures, processor fa...
Page 85 - PLC Fault Table; Table 8. Fault Zoom Help Text for Redundancy Error Codes
4 74 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 PLC Fault Table The following table lists fault zoom Help text and messages for error codes associatedwith the redundancy fault group. Table 8. Fault Zoom Help Text for Redundancy Error Codes ErrorCode Message Fault ...
Page 86 - Faulting RCMs, Losing Links, and Terminating Communications
4 75 GFK-0827 Chapter 4 Operation Faulting RCMs, Losing Links, and Terminating Communications There are distinct differences between losing a redundant communications link, faultingan RCM, and terminating communications. Faulting the RCM module occurs only when a hardware related failure occurs such...
Page 88 - Fault Actions in a CPU Redundancy System; Table 9. Maskable Fault Group Descriptions
4 77 GFK-0827 Chapter 4 Operation Fault Actions in a CPU Redundancy System Fault actions in the Hot Standby CPU Redundancy System are handled differently thanthose in a non-redundancy (Simplex) system. Whenever there is a ”ready ” backup unitconfigured in the system, the fault actions in the active ...
Page 89 - Table 10. Maskable Fault Group Actions
4 78 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 Table 10. Maskable Fault Group Actions Fault Action Fault Group Simplex Mode Redundant Mode User Configurable LOSS_RACK Non-Fatal Fatal Yes LOSS_IOC Non-Fatal Fatal Yes LOSS_IO_MOD Non-Fatal Non-Fatal Yes LOSS_OTHR_M...
Page 90 - Table 11. Non-Maskable Fault Group Descriptions
4 79 GFK-0827 Chapter 4 Operation Table 11. Non-Maskable Fault Group Descriptions Fault Group Table Type Description SYS_BUS_FAIL CPU System bus failure. NO_USER_PRG CPU No User ’s Program on Power-up. BAD_USER_RAM CPU Corrupted User RAM detected on Power-up. WIND_CMPL_FAIL CPU Window Completion Fai...
Page 91 - Maintaining Parallel Bus Termination
4 80 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 On-Line Repair With a Hot Standby CPU Redundancy system most system component failures can berepaired by replacing the failed component while the system is on-line. These on-linerepair procedures are possible because...
Page 92 - Power Supply
4 81 GFK-0827 Chapter 4 Operation Power Supply The power supply has adequate internal fault detection which will cause it toautomatically shut down if there is a failure. In an orderly shut down, the power supplywill first assert the ACFAIL signal before it asserts the SYSREST signal. This will give...
Page 93 - Redundancy Communications Link Failures
4 82 Series 90-70 Hot Standby CPU Redundancy User ’s Guide – December 1993 GFK-0827 If an RCM fault is detected, proceed as follows: H STOP the unit with the suspected bad RCM. H Turn power off at that rack. H Unplug the terminated cable from the RCM and replace the module. H Reconnect the terminate...
Page 95 - Redundancy Alternatives
A section level 1 1figure_ap level 1 table_ap level 1 85 GFK-0827 Appendix A Redundancy Alternatives Redundancy Alternatives There are several redundancy alternatives for the Series 90-70 Programmable LogicController. These redundancy options consist of implementation of the redundancyfeature throug...
Page 97 - Table 13. Redundancy Options
A GFK-0827 87 Appendix A Redundancy Alternatives Table 13. Redundancy Options Option Key PLC Scan Sync Data Sync I/O System Output Selection Method Redund. Bus Redund. I/O Selection Guide 1A 2 90-70s no ApplicationLogic [ 90-70(I/O Scanner) HotStandby yes - 2 no Higher Density Analog Inputs Hot Stan...
Page 98 - Series 90-70 Redundancy Through Application Logic
A 88 Series 90-70 Hot Standby CPU Redundancy User’s Guide - December 1993 GFK-0827 Series 90-70 Redundancy Through Application Logic The following restrictions apply using the current Series 90-70 for redundancyapplications requiring synchronization (these restrictions do not apply to the Hot Standb...
Page 99 - Index
Index 89 GFK-0827 A Acronyms, list of, 12 Active and backup sweeps, 59 Active unit, 2 , 4 , 7 , 8 , 9 , 16 , 19 , 20 , 21 , 25 , 57 , 58 , 59 , 60 , 61 , 65 , 68, 71 , 72 , 77 , 78 , 80 Appendix A, redundancy alternatives, 85 ASCII identifier for control strategy, 58 B Background user checksum, 69 B...
