Analog Input (AI) Object

Transcription

1 Issue Date April 9, 2003 TECHNICAL BULLETIN Analog Input (AI) Object Analog Input (AI) Object...3 Introduction... 3 Key Concepts... 4 Defining the AI... 4 Modifying and Monitoring the AI... 6 Overview of Operation... 6 Hardware Interface Mapping to a DCM Mapping to a DCM Mapping to an N2 Open ASC Mapping to System 9100 Controllers Mapping to LONWORKS Compatible Devices Mapping to an FPU Mapping to a DSC Unreliable and Communication Status Input Processing Analog-To-Digital Conversion Filter Tolerance...21 Ranging Filtering Square Root Function Spanning Override Command Current Value...39 Alarm Limit Analysis Alarm/Warning Delay COS Reporting Johnson Controls, Inc. Code No. LIT Software Release 12.00

2 2 Analog Input (AI) Object Technical Bulletin Triggers and History Control Process Triggering Point History Detailed Procedures Defining an AI Object Online at the Workstation Using Method One to Determine Linearization Parameters Using Method Two to Determine Linearization Parameters Reference Tables AI Attribute Table AI Command Table... 75

3 Analog Input (AI) Object Technical Bulletin 3 Analog Input (AI) Object Introduction An Analog Input (AI) object is the software representation of a hardware device that is monitoring an analog (continuously variable) value. The primary function of an AI object is to convert the raw hardware signal (analog-to-digital counts) from an analog input device to data that can be used in operator displays, alarm limit analysis, and control processes. Typical applications for an AI object include temperature, humidity, pressure, and flow sensors. An AI might be used to measure the discharge air temperature of an air handling unit, or to measure the amount of chilled water (flow) from a chiller. This document explains the relationship between various AI attributes from an applications perspective. In addition, you ll find an alphabetized listing of all AI attributes and commands (with descriptions and acceptable entries) at the end of this document. This document also describes how to: define an AI object online at the workstation use method one to determine linearization parameters use method two to determine linearization parameters

4 4 Analog Input (AI) Object Technical Bulletin Key Concepts Defining the AI Setting values for the AI attributes is called defining the AI. The AI object can be defined: online, using the Operator Workstation (OWS) AI Object Definition window offline, using the Graphic Programming Language (GPL) Database Template. See the GPL Programmer s Manual for instructions. offline, using the Data Definition Language (DDL). See the DDL Programmer s Manual for instructions. See the Defining an AI Object Online at the Workstation section for instructions on defining AI objects. Most of the fields in the Definition window are already filled in with default values. Users must fill in the fields without defaults and make any necessary changes. GPL Template Default attribute settings are also available in the GPL template. Figure 1 shows the GPL Database Template for the AI object.

5 Analog Input (AI) Object Technical Bulletin 5 ANALOG INPUT OBJECT (AI) IDENTIFICATION ENGINEERING DATA System Name = Analog Units = DEG F Object Name = Decimal Position = 1 Expanded ID = High Alarm Limit = 80.0 HARDWARE System Name Object Name H/W Type = = = DCM140 Low Alarm Limit Setpoint Normalband Differential = = = = Slot Number Analog Type Filter Weight Flow Coefficient Span Low Input Span High Input Span Low Output = = = = = = = 1 1K ohm HARDWARE (cont.) STD Range Type Linear. Parm. 1 Linear. Parm. 2 Linear. Parm. 3 Linear. Parm. 4 = = = = = Span High Output = Point Type = AI F10 - SAVE, ESC/mouse click - CANCEL, PGDN - PAGE ANALOG INPUT OBJECT (AI) FLAGS REPORT TYPE Auto Dialout = N Normal = NONE Enable PT History = Y Warning = NONE Save PT History = N Alarm = NONE Comm Disabled = N Override = NONE PARAMETERS MESSAGES Delay = 1 min Warning # Alarm # = = 0 0 Graphic Symbol # = 0 Operating Instr. # = 0 F10 - SAVE, ESC/mouse click - CANCEL, PGUP - PAGE aieng2 Figure 1: AI GPL Database Template Displaying Default Settings

6 6 Analog Input (AI) Object Technical Bulletin Modifying and Monitoring the AI Overview of Operation Table 1: AI Operation Categories Once the AI is defined, you can modify its attributes using the AI Focus window. You also use the Focus window to monitor and command the AI. See the Operator Workstation User s Manual for information on using Focus windows. You can modify the AI object: online, using the OWS AI Object Focus window offline, using Graphic Programming Language (GPL) Database Template offline, using Data Definition Language (DDL) If you need more information on data entry procedures, see the Operator Workstation User s Manual and GPL Programmer s Manual. Refer to the Control System (CS) Object Technical Bulletin (LIT ) for corresponding point mapping tables. AI software functions can be divided into the four basic categories shown in Table 1. Category Hardware Interface Input Processing Alarm Limit Analysis Triggers and History Description An AI hardware device, such as a humidity sensor, is connected to a controller or control module (for example, Digital Control Module [DCM], DCM140, Application Specific Controller [ASC], Variable Air Volume Modular Assembly [VMA], Field Processing Unit [FPU], or Digital System Controller [DSC8500]). The hardware device detects raw analog data, such as varying voltage, current, or resistance. The raw data is sent to the controller or control module where input processing occurs. The hardware input is processed by software calculations, including ranging, filtering, square root extraction, and spanning. The AI current value is compared against user-defined limits to determine the object s status (normal, alarm, or warning). The status can then be routed as a Change-of-State (COS) report, and associated message, to operator devices. AI attribute changes can be used for other purposes, including triggering control processes and historical archiving.

7 Analog Input (AI) Object Technical Bulletin 7 Figure 2 illustrates the general operation of an AI object. The blocks represent functions performed by the software. Each major block (software function) is summarized after the figure, and then explained in detail throughout this document. Hardware Interface Analog to Digital Conversion Filter Tolerance (FPU only) Ranging Filtering Square Root Function Spanning Override Command Current Value Alarm Limit Analysis Alarm/Warning Delay Point History Change-of-State Reporting Control Process Triggering aieng3 Figure 2: AI Functional Flow Diagram

8 8 Analog Input (AI) Object Technical Bulletin Table 2: Function Descriptions by Category Category Function Description Hardware Interface Input Processing Hardware Input Analog-to-Digital Conversion Filter Tolerance Ranging Filtering Square Root Function Spanning Override Command Current Value Continued on next page... The AI sensor detects raw analog data, such as varying voltage, current, or resistance The input circuitry of the controller converts the raw analog data to digital counts Filter Tolerance is used to calculate a filter increment. Whenever the absolute value of the difference between the currently stored value and the newly sensed value is greater than the filter increment, the new value is stored as the current value and COS processing begins. If the absolute value of the difference is less than the filter increment, the newly sensed value is discarded. (Filter Tolerance applies only to AIs mapped to FPUs.) The analog-to-digital counts are then converted to operator readable data (linear and nonlinear), such as degrees Fahrenheit or velocity pressure. When the AI is defined, two to four linearization parameters may be designated. Two parameters are entered for linear data, more than two for nonlinear data. If these parameters are not specified, the software defaults to a 1000-ohm, nickel temperature sensor range. (Ranging definition does not apply to the DSC8500, N2 Open, System 9100 devices, or LONWORKS compatible devices. This function is performed locally at the hardware using locally defined parameters.) An optional filter weight attribute may be set for the AI object during database generation. The filter weight value is used in a calculation that smoothes out erratic AI readings, such as spikes and analog noise. Filtering is used to reduce false alarms and unnecessary control process triggering, resulting from input fluctuations. (Filtering applies only to AIs mapped to DCMs and DCM140s.) This is an optional AI attribute setting that provides for a square root calculation on the ranged analog input value. The software uses an operator-defined flow coefficient in a computation to convert flow sensor inputs, such as velocity pressure to engineering units, cubic feet per minute (cfm) or gallons per minute (gpm). The AI value prior to square root extraction, such as inches of water, is still available for operator viewing (which may be useful for sensor calibration). (Square root extraction does not apply to the N2 Open, System 9100, or LONWORKS compatible devices.) Upper and lower bounds (span) may be defined for the Analog Input object. Span is entered as two values that set the input range, and two values that set the output range. For example, a humidity sensor might operate in a range of 30-80%. The span function prevents values outside this range. (Spanning does not apply to the N2 Open, DSC8500, System 9100, or LONWORKS compatible devices.) You can issue a manual Override command from an OWS. If you override the AI, you are telling the rest of the system to ignore the field input from the AI device. The software will treat the AI as though it is in the state specified by the Override command. (Not available for an AI mapped to a System 9100 or LONWORKS compatible device.) The current value of the AI is the hardware value after it has been ranged, filtered, square root extracted, and spanned. Filtering, square root extraction, and spanning are optional functions, so the current value could be the ranged hardware input.

9 Analog Input (AI) Object Technical Bulletin 9 Category (Cont.) Alarm Limit Analysis Triggers and History Function Alarm Limit Analysis Alarm/Warning Delay Change-of-State (COS) Reporting Control Process Triggering Point History Description High and low alarm limits may be defined for the AI object. If the AI current value falls outside the high or low alarm limits, an alarm is generated. In addition, a setpoint and normalband may be designated so that the software can compute high and low warning limits. If an AI current value falls between an alarm and warning limit, a warning is issued. Other attributes, such as Differential, also play a role in alarm limit analysis. This optional function delays COS reporting of the AI object for a user-defined period of time. The purpose of Alarm/Warning Delay is to prevent nuisance reports. Alarm/Warning Delay, COS Reporting, and Triggers and History are performed by the Network Control Module (NCM). The Alarm/Warning Delay mode is selectable on a per-ncm basis via WNCSetup (see NCSETUP for Windows Technical Bulletin [LIT d]). Select one of the following: Warning Delay mode (default): The delay starts due to an AI setpoint change when the AI is used as feedback for an Analog Output Setpoint (AOS) object. Warning COS reporting is delayed, Alarm COS reporting is not delayed. The delay time is defined in minutes (0 to 255). Alarm Delay mode: The delay starts due to an AI setpoint change when the AI is used as feedback for an Analog Output Setpoint (AOS) object or when the AI current status changes because of a field change. The current status change starts the timer if the change is normal to warning, warning to alarm, or normal to alarm. The timer does not start if the change is alarm to warning, alarm to normal, or warning to normal. Warning and alarm COS reporting is delayed. The delay time is defined in minutes (0 to 255). Note: The Alarm Delay mode has no effect on an NCM that uses the Network Port or JC/85 Gateway download code type. The Alarm Delay mode is not supported on NCM101/102/401. If an alarm is detected, it may be reported at one or more OWSs or printers. OWSs and printers only receive the alarm report if they were defined as report stations for the particular object during the database generation process. (Refer to the Report Router/Alarm Management Technical Bulletin [LIT ] for detailed information.) The timer is killed if the status goes into the normal range and a COS started the timer. The timer is not killed when the timer was set by the setpoint change. An alarm condition and other attribute changes can trigger (cause) a control process to run. Certain attributes of the Analog Input object may be sent to a point history file.

10 10 Analog Input (AI) Object Technical Bulletin Hardware Interface The AI can map to the following hardware devices: DCM DCM140 N2 Open Application Specific Controllers (Air Handling Unit [AHU], Unitary [UNT] controller, Variable Air Volume [VAV] controller, VAV Modular Assembly [VMA], Metasys Integrator Unit, Phoenix Fume Hood [PHX] controller) System 9100 (LCP, DX9100, DX91ECH, DC9100, DR9100, TC9100, XT9100, XTM) LONWORKS compatible devices (LONTCU, LONTCUA, LONVMA, LONVMAA, LONDXA, LONDXAA, LONDXD, and LONDXDA). LONTCUA, LONVMAA, LONDXA, and LONDXDA apply to American sites only. All other sites use LONTCU, LONVMA, LONDXA, and LONDXD. FPU DSC8500 Mapping means: The analog input device is connected to a specific place on a specific controller. This place is referenced in software so that the AI object knows where to: (1) receive input signals, and (2) issue output commands. Figure 3 is a flow diagram of AI hardware interface. The blocks represent software functions. The dashed boxes represent the attributes that define or control the functions.

11 Analog Input (AI) Object Technical Bulletin 11 Function Attribute Hardware Input Hardware System Name System 9100 or LONWORKS Controller Hardware Reference Hardware Object Name Application Specific Controller Point Type Point Address DCM Slot Number Analog Type Hardware Interface FPU Slot Number Filter Tolerance DSC8500 Logical Point Type Logical Point Number Point Type Slot Number Analog Type Subslot Number DCM140 aieng4 Figure 3: AI Hardware Interface This section explains the attributes you use to establish the hardware interface between the AI and the appropriate device. The following attributes in Table 3 are common to all devices. Table 3: Common Hardware Attributes Attribute Hardware System Name Hardware Object Name Description Must be of an existing system, such as NC5. It might represent the control panel or Network Control Module that is handling the AI. The name of the hardware device (for example, the name of the DCM, DCM140, N2OPEN device, System 9100 device, LONWORKS compatible device, DSC8500, or FPU) to which the object is mapped. This object must be defined already. If it is not defined, define it before you define the AI. The remaining hardware interface attributes depend on which type of device you specify for the Hardware Object. For example, if you specify a DCM, the Slot Number and Analog Type attributes are applicable. If you specify a DSC8500, Logical Point Type and Logical Point Number attributes are applicable.

12 12 Analog Input (AI) Object Technical Bulletin Mapping to a DCM An AI maps to any one of the ten universal inputs on the Digital Control Module (DCM). The DCM converts the raw analog signal from a field device to digital counts. The DCM then takes the analog-to-digital counts and performs a number of operations, including ranging, filtering, square root extracting, spanning, and alarm limit analysis. An Input Function Module (FM) provides the interface between the analog input and DCM. Attributes Linking the DCM and the AI Object Besides the Hardware System and Object names, two attributes (described in Table 4) link the AI and the DCM: Slot Number Analog Type Table 4: Attributes that Link the AI and DCM Attribute Slot Number Analog Type Description Represents the Function Module (FM) slot (1 through 10) where the AI device is connected. The AI is actually wired to a terminal on the terminal strips. This terminal is electrically connected to a specific FM slot. Enter a value from 1 to 10. The default is 1. Identifies the sensor that is connected to the DCM. Acceptable entries include 1 K ohm, 100 ohm, or volt/ampere. The default setting is 1 K ohm. This attribute provides the DCM with correct gain stage information for the sensor input. Mapping to a DCM140 An AI maps to any one of the 20 universal inputs on the DCM140. The DCM140 converts the raw analog signal from a field device to digital counts. The DCM140 then takes the analog-to-digital counts and performs a number of operations, including ranging, filtering, square root extracting, spanning, and alarm limit analysis. An Input Function Module (IAN101) provides the interface between the analog input and DCM140.

13 Analog Input (AI) Object Technical Bulletin 13 Attributes Linking the DCM140 and the AI Object Besides the Hardware System and Object names, four attributes (described in Table 5) link the AI and the DCM140: Point Type Analog Type Slot Number Subslot Number Table 5: Attributes that Link the AI and DCM140 Attribute Point Type Analog Type Slot Number Subslot Number Description Represents the type of Function Module to which the AI device is connected. Entering MAI indicates the Input Analog Function Module (IAN101) is being used. Entering AI indicates one of a number of different FMs is being used. Identifies the sensor connected to the DCM140. The Analog Type attribute provides the DCM or DCM140 with correct gain stage information for the sensor input. Acceptable entries include 1 K ohm, 100 ohm, volt/ampere, or v/a low end rel. The default setting is 1 K ohm. The Analog Type v/a low end rel is available if the specified Point Type is AI or MAI. The Analog Type 100 ohm is available only if the specified Point Type is AI. Note: The v/a low end rel option provides for reliable signals at 0 volts. This accommodates transducers that have valid values at 0 volts. Represents the Function Module slot (1 through 10) where the AI device is connected. The AI is actually wired to a terminal on the terminal strips. This terminal is electrically connected to a specific FM slot. Enter a value from 1 to 10. The default is 1. Represents the IAN101 Input Analog Function Module subslot (1 or 2) where the AI device is connected. The AI is actually wired to a terminal on the terminal strips. This terminal is electrically connected to a specific IAN101 subslot. Enter a value from 1 to 2. The default is 1.

14 14 Analog Input (AI) Object Technical Bulletin Mapping to an N2 Open ASC Analog Input objects can map to N2 Open Application Specific Controllers (AHU, UNT, VAV, VMA, MIG, PHX, VND [vendor]). The Application Specific Controller (ASC) converts the digital counts to an analog signal and performs alarm analysis. Attributes Linking the AI Object and the N2 Open ASC Besides the Hardware System and Object Names, two attributes (described in Table 6) link the AI object and the ASC: Point Type Point Address Table 6: Attributes that Link the AI and ASC Attribute Point Type Point Address Description Identifies the type of point in the controller to which the AI will be mapped. It must be an Analog Input (AI) point. Specifies the address of the AI point in the controller to which the AI will map. The range depends on the type of ASC the AI is mapped to: AHU: AI 1 to 8 UNT: AI 1 to 12 VAV: AI 1 to 12 VMA: AI 1 to 5 MIG: 1 to 256 PHX: 1 to 40 VND: 1 to 256 Note: GPL cannot define AI 13 or AI 14 for the UNT and VAV, but if these addresses are already defined in the database, they can be viewed in GPL. IMPORTANT: If you are mapping a CS object attribute and a standard object to the same hardware reference (the hardware reference is the combination of the point type and point address), make sure the Override and Adjust flags are set to No (False) for the CS object attribute. This ensures that there is only one command path to the hardware reference.

15 Analog Input (AI) Object Technical Bulletin 15 Mapping to System 9100 Controllers AI objects can map to System 9100 devices. An AI can map to a System 9100 device that is connected to a Fire or Access NCM200. However, an AI cannot map to a System 9100 device that is connected to a Fire NCM101. A System 91 NCM101 does not support the TC9100. The Echelon Bus (N2E) version of the DX controller (DX91ECH) must be connected to an NCM300 or NCM350. Attributes Linking the AI Object and the System 9100 Device Besides the Hardware System and Object Names, two attributes (described in Table 7) link the AI object and the System 9100 device: Hardware Device Type Hardware Reference Table 7: Attributes that Link the AI and System 9100 Device Attribute Hardware Device Type Hardware Reference Description Identifies the type of System 9100 device to which the AI is mapped. The options are LCP, DC9100, DR9100, TC9100, DX9100, DX91ECH, XT9100, and XTM. Specifies the address of the point in the device to which the AI is mapped. The range depends on the type of System 9100 device. Valid System 9100 device types and hardware references are shown in Table 8. Table 8: System 9100 Device Types and Hardware References Device Type Hardware References LCP/DC9100 AI1-8 and TOTAL1-2* (DO-9100 only) DR9100 AI1-4 TC9100 AI1-4 DX9100 AI1-8, XT1-8AI1-8, CNT1-8*, PM1-12AC1-8*, and XT1-8CNT1-8* DX91ECH AI1-8, XT1-8AI1-8, CNT1-8*, PM1-12AC1-8*, and XT1-8CNT1-8* XT9100 AI1-8, CNT1-8*, and XT1-8AI1-8* XTM AI1-8, CNT1-8* * These Hardware (H/W) references represent 4-byte counter values in System 9100 devices. They can be mapped either to ACM or to AI objects. When mapped to AI objects, their value is an integer in the range of 0 to 9,999,999 and the following parameters are fixed: Decimal Display = 0 Differential = None Setpoint = None Warning Message Number = None Normalband = None Warning Delay = 0 Low Alarm Limit = None Warning Report Type = None The value displayed in the AI object is the value of the counter in the controller. The ACM object reads only the counter differential each minute and calculates its own value, which is different from the value of the counter in the controller unless the operator synchronizes the values.

16 16 Analog Input (AI) Object Technical Bulletin Mapping to LONWORKS Compatible Devices AI objects can map to LONWORKS devices. LONWORKS devices must be connected to a LONWORKS compatible NCM. Attributes Linking the AI Object and the LONWORKS Compatible Device Besides the Hardware System and Object Names, two attributes (described in Table 9) link the AI object and the LONWORKS compatible device: Hardware Device Type Hardware Reference Table 9: Attributes that Link the AI and LonWorks Compatible Device Attribute Hardware Device Type Hardware Reference Description Identifies the type of LONWORKS compatible device to which the AI is mapped. Device types include LONTCU, LONTCUA, LONVMA, and LONVMAA. Specifies the address of the point in the device to which the AI is mapped. The range depends on the type of LONWORKS compatible device. Valid LONWORKS compatible device hardware references are: xxaixxx (The x s are placeholders for specific addressing numbers and characters; see the LONWORKS Compatible Devices Supported by NCM350 Technical Bulletin [LIT ] for details.) Mapping to an FPU AI objects can map to a FPU. The FPU converts the raw analog signal from the field device to digital counts (1 to 2046). The S2 NCM then takes the analog-to-digital counts and performs a number of functions, including comparison to filter tolerance, ranging, square root extracting, spanning, and alarm limit analysis.

17 Analog Input (AI) Object Technical Bulletin 17 Attributes Linking the AI Object and the FPU Besides the Hardware System and Object Names, two attributes (described in Table 10) link the AI and FPU: Slot Number Filter Tolerance Table 10: Attributes that Link the AI and FPU Attribute Slot Number Filter Tolerance Description Identifies the input address on the FPU where the field device is connected. The range is Is a value used in connection with the currently stored value or the object s current value to determine if COS processing is done. The range is 0.2 to 100%. Mapping to a DSC8500 When using CAL1 to define a DSC8500 point that will be mapped to a Metasys Network object, you must enable status reports to the Building Automation System (BAS) for the point. Conversely, if the point will not be mapped to a Metasys object, you must disable status reports to the BAS for the point or you will see an increase in errors in the NCM error log and a decrease in Network Controller (NC) idle time, which will reduce NC efficiency. AI objects can map to a DSC8500. The DSC8500 converts the raw analog signal from the field device to digital counts and then converts the analog-to-digital counts to an analog value. This analog value is then received by the S2 NCM for square root extraction, spanning, and alarm limit analysis. Attributes Linking the AI Object and the DSC8500 Besides the Hardware System and Object Names, two attributes (described in Table 11) link the AI object and the DSC8500. Logical Point Type Logical Point Number Table 11: Attributes that Link the AI and DSC8500 Attribute Logical Point Type Logical Point Number Description Identifies the type of point in the DSC8500 to which the AI will be mapped. For the AI, the LPT can be ASP, ADP, LTD, FUL, RAT, TOT, and INC. Identifies the input address on the DSC8500 where the field device is connected. The range is

18 18 Analog Input (AI) Object Technical Bulletin Unreliable and Communication Status Unreliable Status The AI object may become unreliable due to an offline condition (communication break) or faulty field hardware. When the AI object is unreliable, the following attributes that are derived from the hardware input also become unreliable: Current Value High Alarm Status* Status High Warning Status* Display Filtered Value* Normal Status* Previous Filtered Value* Low Alarm Status* A/D Count* Low Warning Status* * These attributes are invisible to the user. They do not appear as fields at the AI Object Focus window or NT display. However, you might use them in control process programming. Keep in mind that if these attributes become unreliable, they can affect the results of the control process. See Table 23 at the end of this document for additional information on these attributes. You can determine if an object is unreliable by looking at its Focus window or any summary containing information about the object. When the object is unreliable, the current value and Status attributes will display???? (question marks) rather than a value. Figure 4 shows a Focus window for an offline, unreliable object. Communication Status The Comm. Status field in the Object Focus window is used for both online/offline status and disconnect status. (Disconnect status applies to N2 Dialer Module (NDM) applications only). An object is considered offline when there is a communications break between the controller to which the object is mapped and the NCM or NDM to which the controller is connected. If an object is offline, OFFLINE will appear in the Comm. Status field of the object s Focus window. Figure 4 shows a Focus window for an object that is offline and unreliable. In addition, an offline object appears in the Offline summary. If it is an NDM application, and the remote NDM is disconnected from the local NDM, DISCONCT will appear in the Comm. Status field. If the NDMs are connected, either ONLINE or OFFLINE appears in the field, indicating the status of the mapped controller.

19 Analog Input (AI) Object Technical Bulletin 19 Analog Input Focus [DCM140] Item Edit View Action GoTo Accessory Help BLDG-1 AHU-1 DISCH Discharge Air AHU-1 Point History Current Trend System Name Object Name Expanded ID Current Value Graphic Symbol # Operating Instr. # AHU-1 DISCH DISCHARGE AIR 0 20???? Hardware: DCM140 System Name NC5 Object Name DCM2 Point Type MAI Slot Number 1 Subslot Number Analog Type 1 V/A Low End Rel Reports Locked Trigger Locked Comm. Disabled Comm. Status S/W Override Status Flags Auto Dialout Enable PT History Save PT History N N N OFFLINE N???? N Y N Parameters Delay Time 25 Delay Active N Standard Range Type 1 Flow Coefficient Span Low Input Span High Input Span Low Output Span High Output Engineering Data Analog Units Decimal Position High Alarm Limit Low Alarm Limit Setpoint Normalband Differential Filter Weight DEG F Report Type NORMAL WARNING ALARM OVERRIDE Messages Warning # Alarm # STATUS STATUS CRIT3 FOLLOWUP 0 3 aieng5 Input Processing Figure 4: Focus Window for an Offline, Unreliable Object Figure 5 is a flow diagram of AI Object Input Processing. The blocks represent software functions. The dashed boxes represent the attributes that define or control the functions.

20 20 Analog Input (AI) Object Technical Bulletin Hardware Input Analog to Digital Conversion Function Attribute DCM, DCM140, and FPU Standard Range Type Linearization Parameter 1 Linearization Parameter 2 Linearization Parameter 3 Linearization Parameter 4 Filter Tolerance (FPU only) Ranging DCM and DCM140 Filter Weight Filtering DCM, DCM140, FPU, and DSC8500 Flow Coefficient Square Root Extraction DCM, DCM140, and FPU Span Low Input Span High Input Span Low Output Spanning Span High Output Operator Override Command Override Command Current Value Override Software Analog Engineering Units Current Value Current Value Alarm Limit Analysis aieng6 Figure 5: AI Input Processing Functional Flow

21 Analog Input (AI) Object Technical Bulletin 21 Analog-To-Digital Conversion Filter Tolerance The controller converts the analog data to digital counts. Filter Tolerance applies only to an AI mapped to an FPU. Filter Tolerance is used to calculate a filter increment. Whenever the absolute value of the difference between the currently stored value and the newly sensed value is greater than the filter increment, the new value is stored as the current value and COS processing begins. If the absolute value of the difference is less than the filter increment, the newly sensed value is discarded. The following example of filter tolerance is for an ANT-101 specification: The analog range is 0 F to 100 F. The analog-to-digital count (ADC) range is 1 to The filter tolerance is 1%. The current ADC count is 1000 with its equivalent to 50.5 F. The filter increment is F = (2046-1) x 1 = If the ADC increases to 1010 (equivalent to 51.0 F), the absolute value of the difference in the ADC ( = 10) is less than the filter increment. Therefore, this relatively minor change in the analog input value is not processed for COS, but discarded. If the ADC increases to 1025 (equivalent to 51.7 F), the absolute value of the difference in the ADC (25) is now greater than the filter increment. The NCM will update the object with the new value of 51.7 F and execute COS processing.

22 22 Analog Input (AI) Object Technical Bulletin Ranging Ranging applies only to an AI mapped to a DCM, DCM140, or FPU. Ranging is a software function that converts the Analog-to-Digital Counts (ADCs) to operator readable data, both linear and nonlinear, such as F, C, or velocity pressure. The raw data depends on the type of device in use. For example, the ADC from a humidity sensor could be in volts, while the ADC from a temperature sensor could be in ohms. Once the data is ranged, it can be viewed in object summaries, trend graphs, and other operator displays. The following graphs display ranged analog input values. Figure 6 shows the relationship between transmitter voltage and humidity, while Figure 7 shows the relationship between resistance and actual temperature Volts % 20% 40% 60% 80% 100% %RH aieng7 Figure 6: Voltage vs. Humidity for an HE-6310

23 Analog Input (AI) Object Technical Bulletin Resistance (in ohms) (Thousands) Temperature aieng8 Figure 7: Resistance vs. Temperature How Ranging Works The software performs ranging by using this third order equation: Ranged Value = L1 + (L2 x 10-3 x X) +(L3 X 10-9 x X 2 ) + (L4 x x X 3 ) In this equation, X represents the raw input value (analog-to-digital counts), and L (1-4) represents the Linearization Parameters. The calculated linearized value can: either become the AI current value, or get passed on to the Filtering function (optional), Square Root function (optional), and Spanning function (optional)

24 24 Analog Input (AI) Object Technical Bulletin Attributes to Set for Ranging Five attributes (described in Table 12) affect Ranging: Standard Range Type Linearization Parameter 1 Linearization Parameter 2 Linearization Parameter 3 Linearization Parameter 4 Table 12: Attributes that Affect Ranging Attribute Standard Range Type Linearization Parameters (1 to 4) Description Defines the type of AI device you are using, such as a 0-10 VDC transmitter. Use the standard range table (Table 13) to select a standard range. Each number represents a standard sensor device. If you enter a value from for standard range type, the software automatically defines linearization parameters for the device. If you enter 0, you must define linearization parameters. This attribute can be set at an AI Object Definition window or a Graphic Programming Language (GPL) template. Are used in a software calculation that ranges the analog-to-digital counts. The software automatically defines these parameters if you enter a standard range of 1 to 111. If you enter 0, you must define linearization parameters. Customizing non-standard linearization parameters is described in the Non-Standard Linearization Parameters for a DCM or DCM140 and Non-Standard Linearization Parameters for an FPU sections. Standard Linearization Parameters Table 13 lists the standard linearization parameters (1-111). For the DCM or DCM140, use Ranges 1 through 25, and 34 through 111. For the FPU, use Ranges 26 through 33. For the DCM and DCM140, the default linearization parameters type setting is 1, which represents the Johnson Controls 1000-ohm, nickel temperature element. For the FPU, the default is 33, which represents ANT101 0 to 100 F. If your device is not represented in the table, enter 0 for linearization parameters type. This allows you to customize the linearization parameters for the device and application. Customizing non-standard linearization parameters for both the DCM and DCM140 is described in the Non-Standard Linearization Parameters for a DCM or DCM140 section.

25 Analog Input (AI) Object Technical Bulletin 25 Table 13: Standard Range Type AI Devices Linear Parameter For Standard Ranges For DCM or DCM140, use standard ranges 1 to 25, and 34 to 111. For FPU, use standard ranges 26 to 33. Range Type Parm 1 Parm 2 Parm 3 Parm 4 1 DEGF 1000 ohm Ni DEGF 1000 ohm Pl DEGF CPD Silicon DEGF 100 ohm Pl DEGC 1000 ohm Ni DEGC 1000 ohm Pl DEGC CPD Silicon DEGC 100 ohm Pl WC IDP001 0/ WC IDP002 0/ WC IDP005 0/ WC IDP010 0/ WC IDP030 0/ WC IDP050 0/ WC IDP100 0/ mbar IDP001 0/ mbar IDP002 0/ mbar IDP005 0/ mbar IDP010 0/ mbar IDP030 0/ mbar IDP050 0/ mbar IDP100 0/ The following ranges display ma or VDC. Use span function to show appropriate engineering units. 23 4/20 ma input /10 VDC input If you use the AI with a Delta-P sensor to calculate flow, you cannot use Ranges 23 or 24; you must range the AI to match the sensor. 25 W560/HE /5 VDC For FPU, use standard Ranges 26 to 33. For DCM or DCM140, use standard Ranges 1 to 25, and 34 to ANT to 38 C (0 to 100 F) ANT102 5 to 60 C (40 to 140 F) ANT to 66 C (-50 to 150 F) ANT to 122 C (-50 to 250 F) ANT to 100 F (-18 to 38 C) ANT to 140 F (4 to 60 C) ANT to 151 F (-46 to 66 C) ANT to 250 F (-46 to 121 C) Continued on next page...

26 26 Analog Input (AI) Object Technical Bulletin Linear Parameter For Standard Ranges (Cont.) Range Type Parm 1 Parm 2 Parm 3 Parm 4 If you are adding an ANV, ANC, or ANP analog card to an AI software object, you must calculate the linearization parameters. You ll find the equations for calculating linearization parameters later in this document. 34 WC IDP250 0/ WC IDPB / WC IDPB / WC IDPB / WC IDPB / WC IDPBO25-2.5/ WC IDPB050-5/ WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / For FPU, use standard Ranges 26 to 33. For DCM or DCM140, use standard Ranges 1 to 25, and 34 to WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / WC DPT / Continued on next page...

27 Analog Input (AI) Object Technical Bulletin 27 Linear Parameter For Standard Ranges (Cont.) Range Type Parm 1 Parm 2 Parm 3 Parm 4 72 WC DPT / mbar IDP250 0/ mbar IDPB / mbar IDPB / mbar IDPB / mbar IDPB / mbar IDPB / mbar IDPB / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / For FPU, use standard Ranges 26 to 33. For DCM or DCM140, use standard Ranges 1 to 25, and 34 to mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT / mbar DPT /

28 28 Analog Input (AI) Object Technical Bulletin Non-Standard Linearization Parameters for a DCM or DCM140 You are responsible for customizing linearization parameters (1-4) if you entered 0 for Standard Range Type. The software accepts any floating point value (number with a decimal point) for linearization parameters (1-4). For a DCM or DCM140, use the equations and examples in Figure 8 to compute the correct linearization parameters. (All of the equations and examples are for linear inputs.) For an FPU, use the equations shown in the Non-Standard Linearization Parameters for an FPU section.

29 Analog Input (AI) Object Technical Bulletin 29 Voltage Input Equation (High Input - Low Input) L1 = Low Input - (High VDC - Low VDC) (High Input - Low Input) L2 = x (High VDC - Low VDC) L3 = 0 L4 = 0 L (1-4) = Linearization Parameters (1-4) x Low VDC Voltage Input Example (100-0) L1 = Low Input - x = 0-0 = 0 = 0 (5-0) L2 = 20 x = The above calculation is for a W560 Humidity Transmitter with these specifications: 0% RH = 0V 100% RH = 5V Current Input Equation L1 = Low Input - (High Input - Low Input) (High ma - Low ma) (High Input - Low Input) L2 = (High ma - Low ma) x L3 = 0 L4 = 0 L (1-4) = Linearization Parameters (1-4) x Low ma Current Input Example (0.1 - (-0.1)) L1 = (20-0) x 4 = ( x 4) = L2 = (0.1 - (-0.1)) (20-0) x = x = The above calculation is for a static pressure transmitter with these specifications: -0.1 WG = 4 ma +0.1 WG = 20 ma Input Analog Pneumatic (IAP) FM Input Equation (High Input Range - Low Input Range) R1 = Low Input Range - x Low psi (High VDC- Low VDC) (High Input Range - Low Input Range) R2 = High Input Range + x (25 - Low psi) (High VDC- Low VDC) L1 = R1 - [(R2 - R1) x 0.25] L2 = (R2 - R1) x L3 = 0 L4 = 0 L (1-4) = Linearization Parameters (1-4) IAP FM Input Example (100-0) R1 = 0 - x 3 = 0 - ( x 3) = (15-3) (100-0) R2 = x (25-15) = ( x 10) = (15-3) L1 = [( (-25.0)] x 0.25 = L2 = [ (25.0)] x = The above calculation is for an IAP FM, using a T-5210 Pneumatic Temperature Transmitter with these specifications: 0 F = 3 psi 100 F = 15 psi table3 Figure 8: Equations for Computing Linearization Parameters (for a DCM or DCM140)

30 30 Analog Input (AI) Object Technical Bulletin Non-Standard Linearization Parameters for an FPU You are responsible for customizing linearization parameters (1-4) if you entered 0 for Standard Range Type. The software will accept any floating point value (number with a decimal point) for linearization parameters (1-4). For an FPU, use the equations in the following paragraphs to compute the correct linearization parameters. Look for the heading that describes the analog input card you are using: ANP-101, ANV-101, or ANC-101. For a DCM or DCM140, use the equations shown under Non-Standard Linearization Parameters for a DCM or DCM140. ANP Use the following equations to determine the linearization parameters for an AI mapped to an analog input type ANP-101. These equations assume that the Low Potentiometer Value (PVL) is calibrated for 1 count, and the High Potentiometer Value (PVH) is calibrated for L1 = PVL - (L2 x 10-3 ) L2 = 1000 x (PVH - PVL) 2045 L3 = 0 L4 = 0 ANV-101 and ANC Note the input ranges of the ANV-101 or ANC-101 card. Set the jumpers (W1 to W13) on the card to the appropriate input ranges as described in the commissioning sheet for the ANV-101 or ANC-101. If the ANV-101 is using a PET-10n device, use the following equations to determine the linearization parameters. These equations assume the low transmitter (TVL) value is calibrated for 1 count, and the high transmitter (TVH) value is calibrated for L1 = TVL - (L2 x 10-3 ) L2 = 1000 x (TVH - TVL) 2045 L3 = 0 L4 = 0

31 Analog Input (AI) Object Technical Bulletin 31 For an ANV-101 that is not using a PET-10n device, or for an ANC-101, use one of the following two methods to determine the linearization parameters for the AI object. Method One is a shortcut that assumes you have access to information (for example, Hardware and L3 Data Summaries) from the existing JC/85 /40 system. See Using Method One to Determine Linearization Parameters in Detailed Procedures. Use Method Two if this information is not available to you. See Using Method Two to Determine Linearization Parameters in Detailed Procedures. Filtering 2040 Filtering applies only to an AI object mapped to a DCM or DCM140. Filtering is an optional function, which smoothes out erratic AI readings, such as spikes and analog noise. This is helpful for reducing false alarms and unnecessary control process triggering that could result from unfiltered readings. Figure 9 shows how filtering affects an AI flow reading Gallons Flow in Gallons Per Minute (GPM) Unfiltered Value Filtered Value Time (minutes) aieng9 Figure 9: Filtering an AI Flow Reading

32 32 Analog Input (AI) Object Technical Bulletin Attributes to Set for Filtering One attribute affects Filtering: Filter Weight is used in a software calculation that levels out analog input fluctuations. The larger the Filter Weight, the greater the filtering. Leave the Filter Weight blank (the default setting) if you are not using the filter. How Filtering Works The software performs this calculation: Filtered Value = Previous Filtered Value + Unfiltered Value - Previous Filtered Value Filter Weight The filtered value can: either become the AI current value or get passed on to the Square Root function (optional) and Spanning function (optional) Square Root Function Square root extraction applies only to AI objects mapped to a DCM, DCM140, FPU, or DSC8500. Note: If you used Standard Range Type 23 or 24, you must not use the square root function; do not enter a flow value. If the square root function is required, then redo the range parameters to give the velocity pressure (that is, in Water Gauge [WG], not voltage or current). This optional function provides for the conversion of flow sensor input readings, such as velocity pressure, to engineering units like cfm or gpm. It is not used with temperature and humidity sensors, or current/voltage transmitters. The AI value prior to square root extraction, such as inches of water, is still available for operator viewing. (This value may be useful for sensor calibration purposes.) Figure 10 shows the relationship between transmitter input and velocity pressure. This relationship is linear. Figure 11 shows the relationship between flow and velocity pressure. This relationship is nonlinear.

33 Analog Input (AI) Object Technical Bulletin Volts Direct Current (VDC) Velocity Pressure (VP) aieng10 Figure 10: Voltage vs. Velocity Pressure for a JDP Flow in cfm Velocity Pressure (VP) aieng11 Figure 11: Flow vs. Velocity Pressure

34 34 Analog Input (AI) Object Technical Bulletin Attributes to Set for Square Root Extraction One attribute affects square root extraction: Flow Coefficient is used in a software calculation that performs square root extraction on the ranged and filtered AI value. The value you enter for Flow Coefficient is application specific; it should equal 4005 x area of duct in square feet. How Square Root Extraction Works The software performs this calculation: Square Root Output = Flow Coefficient x Analog Input Value The square root extracted value can either: become the AI current value, or get passed on to the Spanning function (optional) The AI value used in the equation is the result of ranging, and if applicable, filtering. (See Figure 2). If the value is negative and there is a flow, use the absolute value and set the result to negative. Spanning Spanning applies only to AI objects mapped to a DCM, DCM140, or FPU. This optional function allows you to set upper and lower bounds (span) on the analog input reading. For example, a humidity sensor might operate in a range of 25-75%. By setting the span, you can prevent values outside this range. Attributes to Set for Spanning Four attributes affect Spanning: Span Low Input Span High Input Span Low Output Span High Output The first two attributes (Span Low Input and Span High Input) define the input range. The next two attributes (Span Low Output and Span High Output) define the output range. Enter information for these ranges according to your application. Decimal or nondecimal values are acceptable. There are no upper or lower limits, although each attribute must be unique.