Building Automation Knowledge Base

Issue When opening a BACnet AnalogInput  from (the Blue) BACnet device side, the value of the object displays as 3 decimal digits by default. The format can be changed in the format field as desired, however when clicking the "Apply" button, an error prompt box pops up with the message "An attempt has been made to write a property defined as inaccessible through the BACnet  protocol write services". if the "Apply" buttonis clicked again, the error disappears and the format is been changed successfully. Product Line Andover Continuum Environment Continuum BACnet BCX1 B3s Cyberstation V2.02 and earlier. Cause Format is not a standard BACnet property, it is a Continuum attribute and when the format is changed Cyberstation sends a command to change the "present value" of the point in the controller. The present value of AnalogInput cannot be written so the error occurs. When clicking "apply" or "OK" for the second time Cyberstation only writes the attribute of the point in the database rather than the controller. Therefore we can get a successful change of format for AnalogInput by clicking "Apply" twice. For AnalogValue, the "present value" of  AnalogValue can be written in BACnet, so there is no error when changing the format of an AnalogValue. Resolution Ignore the error when making the change, click the "Apply" button twice after updating the "Format". Or upgrade to V2.03 where this issue has been resolved.

Issue Alternatives to the FOI1 and FOI2 product which is discontinued and possible replacement using the Westermo ODW-730-F2 Environment Site using a Fiber Optic Interface on LAN (CLAN) or SCU Network (SubLAN) Cause Discontinuation of the FOI1 and FOI2 products which have been available for a number of years. Resolution The ODW appears to provide a very cost effective and versatile fiber optic interface for RS485 networks. The ODW is one of only a few RS485/Fiber interfaces that provide the redundant fiber network capability. Some notable features on the ODW-730-F2 include – -Dual Fiber Bus Configuration or Dual Fiber Redundant Ring Configuration -Local status contact output indicates fiber fault detection -LED indication of Local fiber fault condition (FL L) CH1 and CH2 LEDs indicate if failure is on incoming or outgoing fiber -LED indication of Remote fiber fault condition (FL R) Here the LED indicates when there a fault anywhere in the system. A summary of controller status points monitoring the Local fault detection would be reviewed to identify location of a fault. Current system operation is probably operating on the basis of the redundant ring. A second fiber fault will disable the ring system. In a bus configuration, you currently have lost some portion of the system communications. -Supports Asynchronous (SubLAN) and Synchronous (CLAN) protocols In the case of the synchronous CLAN interface, it is not reconstructing RS485 data quality. Any accumulated distortion on the copper cable segment is passed on to the data through the fiber and will arrive at the other fiber drops in the same condition, although amplitude will be replenished. You must insure you do not exceed copper cable distances and maintain compliance with recommended grade of cable while avoiding stubs and the distortion they produce. -Alternate Fiber Interface Options are supported two receptacles for plug-in fiber transceiver module purchased separately The lowest cost and most common interface is the MLC2. Each of the ODWs in this evaluation were configured with 2 of the MLC2 modules - MLC2 Multimode 62.5/125um or 50/125um 2km Fiber Length - SLC20 Singlemode 9/125um 20km Fiber Length - SLC120 Singlemode 9/125um 120km Fiber Length The ODW also supports the option of bidirectional fiber interface modules. These are more expensive options and currently used infrequently and are not discussed/evaluated here. -Powered by 24VAC (48-62hz), or 12 to 48VDC (supporting redundant DC) Power input is isolated from RS485 and Status port signals -RS485 port is isolated from power AND local ground The RS485 will take on the ground reference of the incoming RS485 signals. An oscilloscope examination of the RS485 data pins with no connection to other RS485 devices will show AC voltage on the RS485 pins (leakage to isolated circuit). A scope should only be examined with the RS485 port connected to the CLAN or SubLAN. Please find the attached pdf ODW FOI EVAL 120824.pdf for review. It proceeds through a sequence of differing configurations with the synchronous controller LAN and the asynchronous SubLAN.

Issue How to configure a TAC Xenta server in Lonmaker when also being used as the communication port in TAC Vista Environment TAC Vista Lonmaker TAC Xbuilder TAC System plug-in Cause Needs to use the Xenta Server as a lonworks device and the Network Interface in TAC Vista. Resolution Using Xenta Server 7xx and LonMaker   Create the Xbuilder project using “stand alone Xbuilder” Add the IO modules that the Xenta Server is using and assign neuron Ids Create the SNVTs for the Xenta Server. Send the project to target.   Create LonMaker and TAC Vista database Create you LonMaker database, register the necessary plug- ins. TAC System plug- in and TAC Device plug- in are used for the Xenta Server. Add the nodes on you Network including the Xenta Server but not the IO modules. You can use a generic template for the Xenta Server and browse in the XIF file. Open system plug-in. Right click on The Xenta server and select “Configure…”. Browse in the Xbuilder project. Click on the “add and mach IO”. Click ok. Go to TAC Network – Settings, Set the Vista communication port to the correct Xenta server type. Also select if you want the IO modules to be commissioned in LNS. Click Ok   Still in the system plug in right click on the Xenta Server and select “set as network interface”. Update TAC Network. Start the server and update TAC Vista Database form the system plug in. Create group bindings if you have any Xenta 401, 30x, 28x controllers. Close the system plug in. Resynchronize the drawing to database. Commission devices. Create bindings. Open TAC Vista workstation, right click and edit the Xenta server (This can also be done form the system plug in configure command). Send the project to target.

Issue Script program Halts with error “Datetime calculation with overflow” resulting in the program not controlling Product Line EcoStruxure Building Operation Environment Observed in versions 4.0.1.86 and 4.0.3.176 Cause When a script program subtracts one datetime from another it can result in a negative value if the datetime being subtracted (subtrahend) is a later datetime than the one being subtracted from (minuend).  This causes the program to halt with error “Datetime calculation with overflow”.  The issue can also occur when a script program calls a function that involves a datetime subtraction resulting in a negative value, for example the standard PID function.   The image below illustrates the issue where DT1 is a later time than DT2.     The problem has typically been seen to occur when using the PID function and the ASP is set to obtain updates from an NTP server.  The PID function uses the current time and the last time the function was called to calculate the time passed, for example: -   TimePassed = CurrentDate – LastTime   Ignoring the date portion consider the scenario where the ASP time is currently 14:01:00 but is one minute ahead of the actual time of the NTP server.  If the function has just been called the LastTime variable will be 14:01:00.  However, in the meantime if the ASP time is updated by the NTP server it becomes 14:00:00 and hence when the function is called again the calculation is: -   TimePassed = 14:00:00 – 14:01:00    This results in a negative value halting the program on error “Datetime calculation with overflow”.   Resolution Either of the two workarounds below can be used but each will need to be considered based on their overall impact.    Use the DIFFTIME function If calling a function check the subtrahend is not a later datetime than the minuend before calling.   This is reported in defect #50263

Issue Device monitoring, alarm priorities and functionality. Environment Sigma versions 4.04 and later. Cause Can the Sigma Device Monitor alarm have its priority or functionality changed? Resolution On Systems using Sigma 4.04 or earlier an alarm produced by the Device Monitor is fixed to priority level 29 and cannot be changed. On Systems using Sigma 4.05 or later a file named deviceMonitor.xml holds timing, retry and other information including the Alarm Priority level as highlighted below: PollFrequency="1001" NumberRetrys="3" AlarmPriority="29" MaxDelayResponse="5000" LogLongDelays="0"> Note: do not change these settings without contacting PSS and fully understanding the implications. The Sigma server will need to be restarted for any changes to take affect. As the alarm is not controller based, it does not have the same functionality as a plant alarm, and therefore cannot be routed or have "actions" applied it. There is no object associated to each controller and therefore it cannot be placed on graphics or referenced in a control scheme. If the customer requires greater functionality, then the old method of controllers being monitored by other controllers, should be used.

Issue Notes from the field  on a Niagara R2 Modbus  RTU integration with an Eaton Series 2000 Xpert Power Meter. Environment I/A Series UNC licensed for the modbus asynch feature Eaton Series 2000 Xpert Power Meter Cause The 3rd party document is vague about  Modbus register-map differences between the IP and RTU protocols. Resolution 1. In order to obtain the Modbus RTU RS-485 map, you must look under the Eaton IQ-250/260 meter. The RS-485 map is NOT located anywhere under the Series 2000 meter. 2. There is also a utility in the "help" button when connecting to the embedded setup & monitoring software on the Eaton Power Meter. The Modbus map can be uploaded as an Excel spreadsheet, however, it is important to note that this map is the TCP/IP Modbus register map, not the RS-485 map. This can be accessed via a standard internet browser utilizing an Ethernet cable connection to the meter. The default IP address is 192.168.1.1. 3. The standard 5 digit Modbus register can be calculated form Eaton's Decimal register number by adding 40000 to the register number listed on their map For example, (register # 1000) (40000 + 1000 = 41000) for the Volts Phase A - Neutral value.  

Issue The FlexAnalog object in the I/A Series R2 programLib jar does not pass the NaN (not a number) to the link when the value at the FlexAnalog input is changed from a valid value to NaN. Product Line TAC IA Series Environment I/A Series R2 Cause The object was based off the standard Analog Input object where the object holds the last valid value when NaN is applied to the input. Resolution There is a jar available that has an updated FlexAnalog object that will pass the NaN to the link when the value at the FlexAnalog input is changed from a valid value to NaN (not a number).  Contact Product Support Services to obtain this jar.

Issue How to reconfigure the IP address of a L-IP if not knowing its IP address? Environment LNS Turbo Lonmaker turbo Lonworks Network Interfaces Loytec L-IP Cause In order to use a L-IP, its IP address need to be known for configuration, otherwise this L-IP cannot functioning at all. Resolution Please follow the steps below to retrieve a L-IP’s IP address. 1. At first prepare a RS232 serial cable of which two sides are 9-pin female connector, or one side is 9-pin female connector and another side is 9-pin male connector. Then one side of the RS232 cable connects to the L-IP’s Serial port (See the red ring of the Figure 1) and another side connects to the PC Serial port (if PC is no Serial Port, the MOXA RS232 USB-to-Serial Adaptor can also be used).                                                         Figure 1：L-IP and PC Connection   2. Use a PC Hyperterminal with the communication settings set to 38,400 bps / 8 data bits / no parity / 1 stop bit / no handshake. On the L-IP use a serial cable (1:1 male-female or female-female cable) to connect COM port (like comm1) on the PC to the Console on the L-IP. Power up the L-IP or press Return if the L-IP is already running. The following menu (See the Figure 2) should appear on the HyperTerminal:                                                                                                                                    Figure 2:Main L-IP menu 3. Select 5 and press Enter, then the following menu (See the Figure 3) would appear on the HyperTerminal. The current IP Address, IP Netmask and IP Gateway of L-IP would be displayed in this menu.   Figure 3: IP Configuration Menu 4. If modifying the IP address, select 2 and press Enter, type in the new IP address behind Enter new IP address and press Enter button (See the Figure 4). Figure 4: Enter new IP address 5. If modifying the IP Netmask, select 3 and press Enter, then type in the new IP Netmask. 6. If modifying the IP Gateway, select 4 and press Enter, then type in the new IP Gateway. 7. After finishing all modifications, select X and press Enter, then save your modifications and return to the main L-IP menu. Please refer to the L-IP user manual for more detailed information.

Issue If the pull-up resistor is disabled falsely, the sensor value or status that connects with this input may be wrong. For example, sensing temperature value has a great deal of error with the actual temperature value. Environment I2 controllers B3 controllers Cause If the pull-up resistor selection is wrong, the right value can not be gotten. Resolution The following is a schematic representation of the switch and its associated pull-up:   To measure temperature, the pull-up resistor switch associated with this input must be enabled. To measure voltage, the pull-up resistor switch associated with this input is usually disabled (OFF). To sense contact closures (Digital signals), the pull-up resistor switch associated with this input must be enabled. To count Pulsing signals or contact closures, the pull-up resistor switch associated with this input must be enabled.

Issue Where can I find Plain English Drivers and documentation for them. Environment Plain English Drivers Cause Schneider Electric Product Support Services does not supply Plain English Xdrivers, nor are they supported. Resolution Schneider Electric does not provide support for Plain English Drivers and no longer provides support for them There are, however, two xdriver manuals available on The Exchange Download Center. Carrier CCN Dataport Manual (32MP, 30GN, 30GB, 30HX, 30GT, 23XL, 19XR, 19EF) Mammoth DDC Manual

Issue Information on Magelis Opti PC Touch Panels Environment Site wanting to use Magelis Opti PC Touch Panels Cause Need information pertaining to the Magelis Opti PC Touch Panels. Sometimes referred to as HMI or Human Machine Interface  Resolution Magelis Opti PC Touch Panels information is located on Exchange Extranet.  Magelis Opti PC Data Sheet Magelis Opti PC Installation Guide Opti PC User Manual Opti PC User Manual (other languages) For the latest HMI software and Release Notes for VijeoDesigner, please visit the following link VijeoDesign

Warning Hazard of Electric Shock: Remove all power from all devices before removing any covers or doors of the system. Disconnect power at the device and at the power source.  Issue The C20 series cameras have the BNC and neutral ground for 24VAC tied to the same ground plane. This can cause a power supply short if the ground and hot are connected out of phase at the power supply. This can also cause ground loop bars in the video if connected to a supply that is not on the same ground plane as the camera. This also causes problems with some third party UTP brands connections. Product Line Field Devices, Pelco Environment C20 cameras connected  to common power supply and/or ground planes that are different. Cause The 24 VAC on the C20 cameras are connected to a common ground plane and the BNC connection is grounded to the same ground plane Resolution When installing the C20 cameras use single isolated transformers for each camera, or make sure the wiring is tied with the same phase. This is done by making sure the same wire leg of each camera is connected to the same wire side of the transformer on the power supply. Also when connecting to the power supply use a meter to test for voltage potential differences. Check that the cameras will work with the third party UTP brand you are using

Issue How to decode the Week Chart Hexadecimal Value in Vista.   Point Name TSCHED.TS09 Channel Name DMAVISTA-LNS-DMA-Channel4-LTG_04_09 Object Name Time Chart - TAC Xenta Week Chart Value 00006270^00001C20^7F~00001D4C^00006270^7F Interpretation [7:00:00 AM - 2:00:00 AM, SMTWTFS] [2:05:00 AM - 7:00:00 AM, SMTWTFS]     Environment Time Schedules Cause  A Hexadecimal Code is generated upon creation or modification of a time schedule. Resolution The Hex code represents seconds after midnight and days of the week, and days of the week that the schedule is on.  An Excel spreadsheet to perform the conversion for you can be downloaded here. In this Example: [7:00:00 AM - 2:00:00 AM, SMTWTFS] [2:05:00 AM - 7:00:00 AM, SMTWTFS],  Is coded to be: 00006270^00001C20^7F~00001D4C^00006270^7F Break down each bracket into parts, here is the first bracketed time elapse: 00006270^00001C20^7F 00006270 =7:00:00 AM 00001C20 =2:00:00 AM 7F=SMTWTFS To decode 00006270 which represents 7:00:00AM: 00006270 (Hex seconds) =25200 (Decimal seconds) 25200/60 (seconds in a minute)= 420 minutes 420 /60 (minutes in an hour) = 7 hours 12AM midnight plus 7 hours is 7:00:00AM  To decode 00001C20 which represents 2:00:00AM: 00001C20=7200 7200seconds = 120 minutes 120 minutes = 2 hours 2:00AM To decode 7F which represents SMTWTFS 7F (Hex days of the week) =127 (decimal) =1111111 (binary)  = SMTWTFS Each bit of a 7 digit binary value is used to represent the day on in the schedule… S=1000000 M=1 T=10 W=100 T=1000 F=10000 S=100000   Here is another example: 0000003C^00000078^04 [12:01:00 AM - 12:02:00 AM, ---W---]  3Ch=60, 78h=120, 04h=0001000

Warning Potential for Data Loss: The steps detailed in the resolution of this article may result in a loss of critical data if not performed properly. Before beginning these steps, make sure all important data is backed up in the event of data loss. If you are unsure or unfamiliar with any complex steps detailed in this article, please contact Product Support Services for assistance. Issue Workstations are no longer logging all points configured for Extended Logging. Lots of these errors seen in the Errors Listview and ACCtrace. "Unable to find Extended Log records to download. This can occur when a log is added to a point through offline editing and the change is never sent to the controller." Product Line Andover Continuum Environment Continuum Cyberstation SQL Server Management Studio Cause What has probably occurred is that in the database the point is set for extended logging but in the controller this same value is not set. It happens when the controller recovers from flash and the database stored in flash didn't have the extended log points configured or it was offline edited. This could also be due to a corrupt entry in the ExtendedLogReservation table that is stopping new points from being assigned. Resolution After the troubleshooting steps in Getting error Unable to find Extended Log records to download have been followed but were unable to resolve the problem, truncating the ExtendedLogReservation table and then rebuilding it did resolve the problem in a number of situations. Please note that this is a brute force approach that requires truncating a table using an SQL query. I want to stress that even after following the below steps to re-enable logging, each affected controller should be reloaded at some point to ensure that it has the most recent up to date information. The steps below are a quicker method of getting the logging start working right away without having to wait to reload each individual controller. The best method to disable and then re-enable the Extended Logging on the points that have it configured is to use individual Listviews filtered to show them. One of Numerics, Inputs, and Outputs. The only change required, and this is a critical one, is to change the "Live Data Refresh Rate" to 0 for each of those three Listviews. This will ensure that the view is not refreshed automatically unless we do this ourselves. See image below for details. After importing the three ListViews, follow the below steps to toggle the ExtLogEnable values for all Numerics that were currently setup to trend. Run the imported listviews, Export the results to CSV files, (do this as a backup so there is a record of what points are currently configured). Edit the listviews to disable live refresh, see attached image for exact details of what to change. [** Important **] Shut down all Cyberstations and backup the ContinuumDB. Go back and confirm that step 4 above has been done. Truncate the entire ExtendedLogReservation table and rebuild it. In SQL Management Studio, run the below query to truncate the table. truncate table ContinuumDB.dbo.ExtendedLogReservation   Start up the Cyberstation Set Workstation to Offline (workstation icon in task tray) Run each of the three Listviews, select Edit->select all, select Edit-> set attribute, set the ExtLogEnable attribute to False, Wait for the changes to take effect on all, you can see when this is done (and it may take awhile) by the tasks in the Distribution Properties window. Then select all again and set the attribute back to True, wait for this to complete. Now when you start up the Workstations you should see that the ExtendedLogReservation table gets populated and slowly start to see that some of the Workstations get assigned logs to start logging. You can see which entries are assigned to a Workstation by the value of ReservingWSLo. This will be set to 0 if no Workstation has been assigned to gather the point yet or it will assigned to the IdLo value of the Workstation that has picked it up.  

Issue Unable to set Units on an AI created in Building Operation Menta Editor The Units drop down list appears but is blank Product Line EcoStruxure Building Operation Environment SmartStruxure (all revisions) Building Operation Menta Editor Analog Input/Output Cause Menta Editor gets the units from Building Operation WorkStation. If the Menta Editor is launched from the Start menu, then there is no connection to WorkStation and units will not be displayed in Menta Editor. This is a known issue which will not be corrected. Resolution All Menta applications should be opened from within the Workstation: Right click on the "Programmable Xenta" object Select "Edit"

Issue Schlage step by step configuration. Environment Windows Xp, 7,  2008, 2008R2 Continuum 1.94 Cause Single Door set Up examples. Resolution Schlage Door setup examples attached.   Download here

Issue Supported Version of Windows Server and SQL Server for StruxureWare Reports Server Environment Reports Server Cause Reports Server is only supported on a specific operating systems and SQL Server versions. Resolution SmartStruxure 1.4.1 and below  Windows Environment: Microsoft Windows Server 2008 R2 (64-bit) SQL Software Options Microsoft SQL Server 2008 R2 Express with Advanced Services (64-bit) SP2 (Download Page - Direct link) Microsoft SQL Server 2008 R2 Standard (64-bit) SP2 (Download SP2: Download page - Direct link)   SmartStruxure 1.5 and above  Windows Environment: Microsoft Windows Server 2008 R2 (64-bit) Microsoft Windows Server 2012 (64-bit) Microsoft Windows Server 2012 R2 (64-bit) SQL Software Options Microsoft SQL Server 2008 R2 Express with Advanced Services (64-bit) SP2 (Download Page - Direct link) Microsoft SQL Server 2008 R2 Standard (64-bit) SP2 (Download SP2: Download page - Direct link) Microsoft SQL Server 2012 Express with Advanced Services (64-bit) SP2 (Download page - Direct link) Microsoft SQL Server 2012 Standard (64-bit) SP2 (Download SP2: Download page - Direct link)

Issue If a Door is unlocked by schedule, for example, during business hours, a door ajar alarm is not available. How can you configure the door if the site would still like to receive a door ajar alarm, alerting them if someone goes through the door and leaves it ajar. Product Line Andover Continuum Environment CyberStation CX9900 CX9702 CX9680 ACX5720 ACX5740 Cause When a door is unlocked by schedule (or timed/permanent unlocked) the Continuum controller by design does not perform door ajar checking until the door re-locks. Resolution Write a PE program to monitor the door's DoorSwitch and set the DoorAjar flag as needed. Care should be taken as to only engage the PE program when the access engine in the controller is shunting the alarm in order to avoid contention. NOTE: Make sure to attach the DoorAjar alarm enrollment to the door. Below is a sample PE program. IMPORTANT: This PE code is provided as a sample ONLY, you can use it as a guideline for creating your own PE programs to perform similar functionality. 'This program monitors a door while the door is unlocked by schedule 'and generates a door ajar alarm if the door is left ajar 'Program is LOOPING and AUTOSTART RESET: MyDoor DoorAjar = False Goto CHECKING CHECKING: If SCH_PNT = On then Goto MONITORING 'when door is not unlocked by schedule let controller handle ajar condition MONITORING: If MyDoor DoorSwitch = Opened then Goto ENSURE_CLOSE If SCH_PNT = Off then Goto RESET ENSURE_CLOSE: If TM > 1 then Goto SEND_ALARM 'if door is left ajar for over 2 minutes report a door ajar alarm If MyDoor DoorSwitch = Closed or SCH_PNT = Off then Goto RESET SEND_ALARM: MyDoor DoorAjar = True If MyDoor DoorSwitch = Closed or SCH_PNT = Off then Goto RESET E: If TS > 30 then Goto RESET

Warning Potential for Data Loss: The steps detailed in the resolution of this article may result in a loss of critical data if not performed properly. Before beginning these steps, make sure all important data is backed up in the event of data loss. If you are unsure or unfamiliar with any complex steps detailed in this article, please contact Product Support Services for assistance. Issue Unable to enable or disable Enhanced Alarm Logging or Enhanced Alarm Delivery flags in Database Initialization. The Enhanced Alarm Logging flag goes back to what it was set to before making the change and the Enhanced Alarm Delivery flag is greyed out and uneditable. Product Line Andover Continuum Environment Continuum Database Initialization Cause The owner of the ContinuumDB is set to something other than the default andover97. In this specific case it was set to SA. The SA user was unable to write these changes to the database hence why the settings kept reverting back. To compound the issue it was found that an andover97 user had been created under the Security folder in the ContinuumDB, this then blocked attempts to change the owner to the correct andover97 user. Resolution Backup the ContinuumDB before making any changes. See Move / Backup / Restore a database on a Single User SQL2005 Express system. Attempt to change the db owner with the below query using the sp_changedbowner stored procedure. Select "New Query" and copy the query text shown below. Run the query. USE [ContinuumDB] GO sp_changedbowner 'andover97' GO If this produces an error "The proposed new database owner is already a user or aliased in the database" then see Unable to change the ContinuumDB database owner using the stored procedure sp_changedbowner for instructions on how to drop the incorrect user so we can use the correct one. After successfully dropping the user from the ContinuumDB, re-run the query in step 2 above to change the database owner to andover97.   After successfully setting andover97 to the database owner you should now be able to toggle the Enhanced Alarm Logging and Enhanced Alarm Delivery options in Database Initialization. If you want these enabled; toggle them both off, update the database, toggle them both on, update the database again. This will ensure they have been enabled properly. Note: The definitive check to see if the Enhanced Alarm logging and Enhanced alarm delivery are both enabled is by checking the dbo.ACCDBVersion table in the SQL database using SQL Server Management Studio (or Express). New Alarm Logging and New Alarm Delivery should both be set to 1.

Issue Alarms or Events are not being received as soon as they occur and there is a large delay before they are written to the Database. Product Line Andover Continuum Environment Continuum Cause Review the controller error log. If there are 6c0e errors, this indicates the comms buffer is filling up (see Controller error log: error transmitting (LAN_ERR_TRANSMIT_ERROR)). Another indicator is in the ACCTRace logs. Check if Alarms are being logged in the Database when the WS thread is receiving them. The time in the ACCtrace may be logged as the TimeOfLog. Investigate the programming to see if it is polling data from a BACnet controller constantly. There may be no delay in poll requests which can overload the controllers comms buffers. This will in turn delay some Alarms from being delivered to the Workstation to be displayed and logged in the Database. Resolution Fix programming so there are wait lines between each poll. Also see Controller error log: error transmitting (LAN_ERR_TRANSMIT_ERROR).