INFO PERTAMEDIKA EDISI 3

8. Process Alarm Handling 8–1



Participant Guide Process Alarm Handling Contents of This Module Module Introduction.........................................................................5  Module Objectives............................................................................5  Reference Documentation...............................................................5  Alarming Hardware Architecture ....................................................6  Process Alarms ................................................................................6  Process Alarm Data Flow ............................................................................. 6  Alarm Handling.............................................................................................. 8  Alarm Types in Foxboro DCS..........................................................8  Alarm Parameters in General ..........................................................9  H/L and HH/LL Absolute Alarm .................................................................... 9  Absolute Alarm Key Parameters (PID Block) .......................................... 10  H/L Deviation Alarm .................................................................................... 11  Deviation Alarm Key Parameters (PID) ..................................................... 11  Key Parameters....................................................................................... 11  Output Alarm ............................................................................................... 12  H/L Out-of-Range Alarm ............................................................................. 12  Out-of-Range Alarm Key parameters (AIN Block).................................... 12  Key Parameters....................................................................................... 12  BAD Alarm ................................................................................................... 13  BAD Alarm Key Parameters (AIN Block)................................................. 13  BAD Alarm, Clamping, and Last Good Value ........................................... 13  Alarm Priority Parameters ....................................................................... 14  Alarm Group Assignment Parameters..................................................... 15  Alarm Indicator Parameters..................................................................... 15  Group Alarm Devices.................................................................... 16  Compound Group Alarm Devices.............................................................. 17  STATION Block Group Alarm Devices ...................................................... 18  Review Questions ......................................................................... 19  5210FV Foxboro System and Software Maintenance with FoxView 8–3 Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide 8–4 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Participant Guide Process Alarm Handling Module Introduction The control system can be configured to identify and notify personnel of a wide variety of abnormal conditions in a manufacturing process. This configuration involves alarm parameters found in compounds and blocks. This module discusses process alarm types and alarm parameter configuration for both alarm generation and handling. Module Objectives Upon completion of this module, you will be able to describe the data flow involved in process alarm handling. After completing this module, you can:  Diagram alarm detection and notification data flow.  Become familiar with the Foxboro™ Alarm Provider and Distributed Alarm System work.  Describe alarm types.  Describe alarm parameters. Reference Documentation For more information, refer to the following materials:  Foxboro I/A Series Block Configurator User’s Guide .....................................B0750AH  Foxboro I/A Series Control Database Deployment User’s Guide................... B0750AJ  Foxboro Control Software Pack Deployment Guide.......................................B0750BA  Foxboro I/A Series Hardware Configuration User’s Guide.............................B0750BB 5210FV Foxboro System and Software Maintenance with FoxView 8–5 Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide Alarming Hardware Architecture Figure 1 shows the hardware architecture for alarming. Figure 1 – Alarming Hardware Architecture Process Alarms Process alarms in the control system are configured to monitor process condition and equipment status. When the process condition exceeds the preset limits, alarms are generated to notify plant personnel of the abnormal condition. Process Alarm Data Flow Alarm generation parameters are configured in the control block. Therefore, process alarms are generated on the block level. A control block can have more than one type of alarm. For example, a PID block has three types of alarms:  Absolute  Deviation  Output Another example is the AIN block which also has three types of alarms:  Absolute  Range  Bad 8–6 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Participant Guide Process Alarm Handling Block alarm parameters configuration includes:  Alarm Enable  Alarm Limits  Messages  Priority  Target Target is typically a group of devices such as printer, historian, workstation and so on that receives the alarm notification. The actual devices in the target group are specified in the compound containing the blocks and/or the Station Block of the CP where blocks reside When an off-normal condition is detected by the block, the following occurs, Figure 2:  An alarm is generated  Notification and messages are then sent to the specified group of devices if the alarm is not inhibited  A historian will collect the Alarm information  The WP will automatically display the alarm to the following:  Block Faceplate  Operator Display  Annunciator Panel  Common Alarm Console  FoxView™ Process Button Figure 2 – General Data Flow 8–7 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide Alarm Handling Foxboro Alarm Provider receives alarm and event messages from Foxboro Control Processors and workstations. It also directs these messages to the InTouch Distributed Alarm Subsystem. The Alarm Provider translates Foxboro alarm messages into the InTouch alarm message format and makes the alarms available to any InTouch alarm client or alarm consumer. Alarm Types in Foxboro DCS Foxboro Distributed Control System (DCS) enables the user to configure alarms to monitor both continuous and discrete process variables. Several types of alarms are provided as follows:  Absolute – Measurement value compared to an absolute limit  High and/or Low: Limit exceeded  High-High and/or Low-Low: Limit seriously beyond the desired value  Deviation – Difference between Measurement and Setpoint exceeded limit High and/or Low: Limit exceeded  Output – Output value compared to an absolute limit High and/or Low: Limit exceeded  Bad – FBM error or I/O error in communicating value Not to be confused with BAD status for a value  Out-of-range – Value out of expected range High and/or Low  Rate-of-change – Value changing too fast  Target – Accumulated value reaching limit  Pre-target: Accumulation approaching target value  Target: Accumulation reached target value  Mismatch – Contact not in desired state after time interval  State – Contact input in alarm state Alarm on 0, Alarm on 1, or Alarm on either  State Change – (STALM block) monitored indicator moved to alarm state  Trip – Watched-for condition occurred  (EVENT block) sequence of events triggered  (MON block) monitored condition tripped 8–8 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Participant Guide Process Alarm Handling  Sequence – Error condition occurred in sequence logic Alarm Parameters in General Each alarm type in a block has its own set of parameters that must be configured. These parameters are shown and described as follows:  Option Turns alarm algorithm on or off  Limit  Alarm limit in Engineering Units  Some blocks have multiple Engineering Unit ranges  Dead band  In percent of Engineering Unit range  Added to low limit or subtracted from high limit to provide return-to-normal point  Helps prevent extra alarm messages when value dithers around limit  Priority Priority of the detected alarm, 1-5  Group  Alarm destination devices are grouped; specifies the group number  1-3, for groups defined in compound parameters  4-8, for groups defined in STATION block parameters  Name  Alarm Text H/L and HH/LL Absolute Alarm Measurement value compared to an absolute limit is as follows:  High or Low limit exceeded  High-High or Low-Low limit exceeded, this is typically used for the operator to take some action because measurement is seriously beyond the desired value Measurement Deadband defines the block's deadband in which the Absolute Alarms will remain active when tripped. 5210FV Foxboro System and Software Maintenance with FoxView 8–9 Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide In Figure 3, when measurement goes down below the Low Alarm Limit, the Low absolute alarm is tripped. It remains tripped until the measurement goes up above the (Low Limit + Deadband). Similarly, when measurement goes up and crosses a High Limit, it will stay in alarm until it goes down below the (High Limit - Deadband). Similar analogy for High-High and Low-Low alarm. Several control blocks have Absolute alarms. In this section, you will use the PID block as an example to implement this type of alarm. Figure 3 – Absolute Alarms Absolute Alarm Key Parameters (PID Block) This section illustrates the key parameters of the absolute alarm. Alarm Enabling To activate a particular alarm, the option associated with that type of alarm must be activated. In other words, the value of the option must be set to a specific value, Refer to the reference document (BO193AX). In the PID block, there are four such alarm options:  Measurement Alarm Option (MALOPT) – Activates absolute alarming  Deviation Alarm Option (DALOPT) – Activates deviation alarming  Output Alarm Option (OALOP) – Activates output alarming  High/High and Low/Low option (HHAOPT) – Activates High/High and Low/Low alarming on the measurement Alarm Value Parameters The PID block contains parameters that define the limits of process variables. When these limits are violated, an alarm is generated.  High/High Alarm Limit – HHALIM: defines the measurement's limit that, when exceeded, triggers an HHABS.  Low/Low Alarm Limit – LLALIM: defines the measurement's limit that when, the measurement drops below the value, triggers an LLABS. 8–10 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Participant Guide Process Alarm Handling  Measurement High Limit – MEASHL: defines the PID's measurement limit which, when exceeded, triggers a High Absolute Alarm (HIABS).  Measurement Low Limit – MEASLL: defines the measurement limit which, when the measurement drops below this value, triggers a Low Absolute Alarm (LOABS).  Measurement Deadband – MEASDB: defines the block's deadband in which the HHABS, LLABS, HIABS or LOABS alarms will remain active. H/L Deviation Alarm Figure 4 shows a Deviation alarm which monitors the amount of deviation of measurement from setpoint. The algorithm is (Measurement – Setpoint) so when the difference exceeds the limit, alarm is tripped. This type of alarm is typically implemented in a controller block (PID). Figure 4 – Deviation Alarms Deviation Alarm Key Parameters (PID) This section illustrates the key parameters of the Deviation alarm. Key Parameters There are three main parameters listed below:  High Deviation Limit – HDALIM: defines the amount by which the measurement can exceed the setpoint before triggering a High Deviation Alarm (HIDEV).  Low Deviation Limit – LDALM: defines the amount by which the measurement can drop below the setpoint before triggering a Low Deviation Alarm (LODEV).  Deviation Deadband – DEVDB: defines the deadband for both HIDEV and LODEV alarms. The Deadband works the same way as previously described 5210FV Foxboro System and Software Maintenance with FoxView 8–11 Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide Output Alarm The Output alarm monitors the output of a block not to exceed the specified alarm limits it operates similar to the Absolute alarm since the output value is compared to an absolute limit. H/L Out-of-Range Alarm Figure 5 shows the Out-of-Range alarm which is typically implemented in the analog input blocks (AIN and MAIN) and used to monitor block’s output not to exceed an expected range. The output range is determined by the block’s output scale plus and minus the OSV parameter. Figure 5 – Out-of-Range Alarms Out-of-Range Alarm Key parameters (AIN Block) This section illustrates the key parameters of the Out-of-Range alarm. Key Parameters The parameters are listed below:  ORAO – Out-of-Range Alarm Option: It is a configurable parameter that enables the alarm.  OSV – Over Span Variance  It is configurable, and it defines the percentage by which the output can exceed the output range specified by the HSCO1 and LSCO1 parameters  The block output clamps at (HSCO1 + OSV) or (LSCO1- OSV)  Low Out-of-Range alarm is generated when the output clamps at (LSCO1- OSV) while a high out of range alarm is generated at (HSCO1 + OSV). 8–12 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Participant Guide Process Alarm Handling BAD Alarm Figure 6 shows the BAD alarming that is initiated when the FBM to which the block is connected becomes non-operational, or optionally, when the input value is high or low out of range. This type of alarm is generated by I/O blocks. In addition, the analog input blocks such as AIN and MAIN can be configured to generate a BAD alarm, not only when the FBM status is bad but also, when the measurement status is bad. BAD Alarm Key Parameters (AIN Block) The BAD alarm is enabled, by configuring the BAO option. The BADOPT parameter can be configured so the BAD alarm can also be generated when the FBM is bad and the measurement is out of range. The BAD alarm is a Boolean output and it is set to 1 when BAO is true and an IOBAD alarm exists, as shown in Figure 6. Figure 6 – Determining BAD Status (AIN Block) BAD Alarm, Clamping, and Last Good Value Figure 7 shows the main parameters, which are as follows:  Clamping – Keeps the converted value within the block’s engineering range as determined by HSCO1 and LSCO1.  OSV – It is shown in percentage of scale and is provided to keep any signals that may be fluctuating at either the low or high end of range from continually resetting the HOR and LOR conditions. 5210FV Foxboro System and Software Maintenance with FoxView 8–13 Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide  LASTGV – Last Good Value When accurately set in the situation described above, it causes the previous value of PNT to be retained, and the value obtained by this cycle to be ignored. Figure 7 – BAD Alarm, Clamping, and Last Good Value Alarm Priority Parameters As mentioned previously, each alarm is assigned a level of importance. Alarm priorities can be set from 1-5 as shown in Figure 8, with 1 representing the most critical alarm. These are as follows:  High/High Alarm Priority (HHAPRI) for high/high or low/low alarming  Measurement Alarm Priority (MEASPR) for absolute alarming on the input  Deviation Alarm Priority (DEVPRI) for deviation alarming  Output Alarm Priority (OUTPRI) for output alarming 8–14 Figure 8 – Alarm Priority Parameters 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Participant Guide Process Alarm Handling Criticality (CRIT) defines an integer output parameter that represents the highest priority alarm occurring in the block. This value ranges from 0-5. A value of 0 indicates that the block is currently not in alarm. Alarm Group Assignment Parameters Figure 9 shows the parameters which identify the group of devices that will receive a particular alarm notification. As mentioned earlier in discussing compound parameters, a maximum of eight devices can be assigned to each group. An additional 16 devices in five other groups can be defined. These are defined in the Station Block as follows:  Measurement Alarm Group (MEASGR) for HIABS and LOABS alarms  Deviation Alarm Group (DEVGRP) for HIDEV and LODEV alarms  Output Alarm Group (OUTGRP) for HIOUT and LOOUT alarms Figure 9 – Alarm Group Assignments Parameters Alarm Indicator Parameters Alarm indicators are Boolean output parameters that are set by the block to indicate the presence (1) or absence (0) of a particular alarm. These are as follows, Figure 10:  High/High Alarm Indicator (HHAIND)  Low/Low Alarm Indicator (LLAIND)  Measurement High Indicator (MEASHI)  Measurement Low Indicator (MEASLI)  High Deviation Alarm Indicator (HDAIND)  Low Deviation Alarm Indicator (LDAIND)  High Output Alarm Indicator (HOAIND) 5210FV Foxboro System and Software Maintenance with FoxView 8–15 Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved

Process Alarm Handling Participant Guide  Low Output Alarm Indicator (LOAIND) Figure 10 – Alarm Indicator Parameters Group Alarm Devices Process alarms are generated by the control block and then sent to the group of alarm devices specified by the alarm group parameters. Each type of alarm in a block has its own alarm group parameters, so in a block that has multiple alarms, each alarm can be sent to a different group of devices (if desired). There are eight groups of alarm devices as shown in Figure 11. Groups 1-3 are defined in the compound while groups 4-8 are defined in the STATION Block. 8–16 Figure 11 – Notification to Alarm Devices 5210FV Foxboro System and Software Maintenance with FoxView Schneider Electric Proprietary and Confidential Information © 2021 Schneider Electric Systems USA, Inc. All Rights Reserved