MLM Integration with BMS Network Protocols

Transcription

1 MLM Integration with BMS Network Protocols The Master Comms Unit 2 (MCU) serves as a gateway to other BMS protocols such as Lontalk or BACnet. The MCU features four diffuser data channels with a capacity of 15 diffusers each, i.e. a total of 60 diffusers can be connected to a single MCU. It also interfaces with the MLM Application. The following physical protocol interfaces are supported: MLM Application (TCP/IP) Magnetic Ethernet BACnet/IP Magnetic Ethernet BACnet ms/tp RS485 bus LonTalk TP/FT 10 bus The following network variables of the MLM Proprietary network are visible to other BMS network protocols. Output from BMS: o Temperature Setpoint BACnet 0.1 C,.5 F resolution Lon 1 C resolution ( F not supported) o BMS command (BACnet only) Drive Diffuser Open to pre set limit position Drive Diffuser Close to pre set limit position Emergency Activation (Disable Heater Output) Emergency Open to physical limit position Emergency Close to physical limit position Activate Back off Band control Set heater to maximum output Occupancy override occupied/unoccupied Occupancy external input occupied/unoccupied Page 1

2 Input to BMS: o Space temperature, C or F o Current heater output, 0 to 100% o Diffuser plate motor position, 0 to 100% o Change Over Sensor (Supply air temperature), C or F o BACnet Mode System Idle (in control temperature band) Initializing Heating mode Cooling mode Motor in manual drive mode Occupancy state occupied/unoccupied o Lon Mode Data from the MCU active Busy initializing Heating mode Cooling mode Identifying, mapping and binding of network variables to other network protocols Master Diffuser concept The MLM Proprietary network can have up to 60 diffusers installed on 4 different channels per MCU. Each channel is connected to a maximum of 15 diffusers. They can be arranged into temperature Zones, with each Zone having one master diffuser that controls the other slave/drone diffusers. Areas of control are designated Zones and comprise a demarked space such as a room, hallway or office area. Each such Zone can contain single or multiple diffusers. One diffuser in such a Zone will be designated a master diffuser and will host the space temperature measurement and setpoint facility. Other diffusers in the same control Zone will be designated slave diffusers and will follow the master control outputs. Page 2

3 Distinguishing between Channel/Loop and Zone designations The Channel/Loop number designates the physical (hardware) connection from the field diffusers to the MCU. From each Power Supply Unit (PSU) a RJ9 data cable connects to a numbered channel on the MCU. During commissioning, diffusers in each channel are grouped according to control area. The number of loops can be from 1 to a maximum of 15 per channel, sequentially allocated to each master. Information between channels can be routed, with a master diffuser on one channel linked to a slave diffuser(s) on a different channel(s). Hence the term Zone is used to indicate the actual group of diffusers that serves a specific area, regardless to which channels that group of diffusers are connected to. For example, the above layout is designated Zone 1: Diffuser with serial number is connected to channel 1, designated loop 1 and is set as a master (temperature reading and setpoint enabled). This diffuser controls the slave diffusers with serial numbers , and , physically connected to channels 1 and 2. During Lon BMS mapping of the data points, the [channel][loop] number of the master diffusers are used as the reference point, i.e. in our example [C1][L1] will be the identifier surfaced to the BMS to indicate control data for Zone 1. In a BACnet BMS system, only the Zone number will be indicated in the Object Description property (duplicated in the Object Name property). NOTE: It is very important to mark the cables from a specific PSU to a specific channel. Swopping cables after commissioning will rearrange the data points on the BMS. Page 3

4 The MLM Application is used to bind the diffusers to their respective control Zones. By using the edit and save feature on the application, diffusers can be grouped and Zone numbers allocated. During commissioning in edit mode, the user is prompted to allocate Zone numbers to diffuser groups. These numbers can be arbitrarily allocated to each control Zone by the user. Once the save button is pressed, the application will automatically allocate sequential Zone numbers as well as [channel][loop] numbers to the project. Zone numbers will be allocated 15 per channel, with channel 1 starting with Zone 1 up to a maximum of Zone 15. Channel 2 will start with Zone 16, irrespective of channel 1 taking up 15 control Zones or not. By the same token the channel 3 Zone numbers will start at 31 and channel 4 starts at Zone number 46. For Lon binding to BMS, a master list must now be generated using the MLM Application, as indicated below. MLM Application rev should be used for this function. The embedded Lon function, available on the MCU rev 1 product, is limited to 40 functional blocks. In practise this means a maximum of 38 control zones can be accessed with Lon (see section MCU Lon module setup below). With BACnet all 60 possible control zones can be accessed at fixed data point locations. MCU to Lon Mapping Table Setup By using the MLM application (Rev 6.19) File/Export Setup command, a list can now be exported to a tab delimited text file of all the master diffusers in the MLM proprietary network. Be sure to select the Master Only box to identify the point reference for the BMS.The table is exported as text in the following format: Page 4

5 Connection Address: Master Comms Device ID: 04CC68C40201 Exporting only masters Channel Type ID HID Loop ChLpMap LonStr Zone Serial Nr DeviceName 1 Interf [1] Brdrm1 2 Interf [2] Off123 3 Interf [3] Off214 4 Interf [4] Off324 The fields of interest are: Type Interface indicates the diffuser controller hardware and in conjunction with the Serial Nr field identifies the actual diffuser selected as master for that control Zone. LonStr Indicates the [channel][loop number] of the physical hardware point. ChLpMap Decimal presentation of the LonStr indicator. Devicename Physical location in the building of the control Zone. It is strongly recommended that this six character identity string is implemented during commissioning. Using the ChLpMap and LonStr columns a mapping table can be built up Depending on which protocol is used. A String or Decimal presentation of the channel and loop number may be needed for the mapping table setup: String Decimal [1] 5 21 [2] 2 34 [3]14 62 [4] 4 68 Page 5

6 MCU Lon module setup Some concepts about the MCU Lon gateway implementation: The Lon configuration file (.xif) should preferably be downloaded from the MCU device during commissioning utilizing the service button. If not the.xif program revision files 3 (standard command set) and 4 (extended command set) is available on the Rickard Trac download site Each MCU is labelled with the unique neuron ID number for that device. The neuron ID is also programmed into the Device ID field on the MCU web page. It is assumed the user is familiar with the standard LNS (Lon Network Service) tools and their implementation. Reference will only be made to these software tools. Should the user wish to utilize the heartbeat (ncisndhrtbt) functionality, the MCU will propagate all the remaining network variables that were not propagated during the previous heartbeat period. There are 40 functional blocks supported in the functional profile of the MCU Lon module. The node and virtual blocks are standard Lon implementations. The balance all utilizes the Lon 8502 Space Comfort Controller template. This in effect means each MCU serves as a gateway for a maximum of 38 master diffuser Zones. The table below shows the functional profile for each control Zone. Page 6

7 By default these Zones are allocated 9 control Zones (functional blocks) per MCU data channel with channel 4 containing 11 control Zones, to make a total of 38. Please note that these defaults are the control Zones that are immediately visible to the BMS (LonMaker) application. Should a channel contain a loop number outside of the allocated defaults, i.e. [channel 1] loop 10, the user can still access that Zone by editing the string value for the [channel] loop number. The ncichlpmap configuration property string value (for example [2] 3) can be changed from the default value by using network tools such as LonMaker. In practise the next visible [channel] loop data point that is not utilized will be edited to the required [channel] loop number string. Thus any [channel] loop number can be made visible on the Lon system, provided a maximum of 38 Zones are not exceeded. Care must be taken not to duplicate the [channel] loop numbers when editing the parameters. Duplicate [channel] loop numbers will only display the first sequential data point, with the second one showing zero. It should be noted at this point that when the diffusers are set up during commissioning with the MLM Application, using the edit/save function will automatically allocate loop numbers to the lowest available loop number for that channel. Therefore it is rarely found that a master Zone point exceeds the default value. The string edit function in LonMaker is more often used to eliminate gaps in the active data points. The nvichlpmap network variable that uses a decimal value (see Table 1) of the channel/loop binding may also be used with networks tools. Page 7

8 MCU BACnet module setup The MCU can support BACnet/IP or BACnet ms/tp. BACnet ms/tp contains a separate hardware interface (module) for the RS485 transceivers whereas BACnet /IP interface directly to the Ethernet tcp/ip port on the MCU. Please note the MCU ms/tp conforms to the RS485 network specification as recommended by ASHRAE. For the interconnection and shielding instructions, refer to Addendum y of ANSI/ASHRAE Standard A major advantage of BACnet/IP implementation is that the MLM Application can run simultaneously with the BMS BACnet application on the same (PC) hardware platform. This greatly simplifies system commissioning and diagnostics. Identification For the BACnet tcp/ip factory activated MCU, type in the IP address on an Internet browser. The following information will be displayed on the web page: The serial number and software revision numbers cannot be edited. The Device Name can be changed by the user to identify the physical location of the MCU. The default unique BACnet device ID (instance) is derived from the Ethernet mac address. This parameter can be changed by the user (edit and press save) to comply with the BMS requirements. Note: The BACnet ID and Device Name fields indicated are contained in the Object Identifier and Object Name properties of the BACnet Device Object. Page 8

9 For an MCU configured as a BACnet ms/tp unit the MS/TP MAC field is activated: The ms/tp mac address is a crucial setting and each MCU must contain an individual mac address for correct operation. When editing this field care must be taken to delete all the blank spaces to the left of the field before entering the new mac address. Please note the ms/tp standard limit for mac addresses are 0 to 127. For optimum data throughput on ms/tp it is recommended that the mac addresses be allocated sequentially from zero. Also the MaxMaster parameter in the BACnet Device Object should be set to the highest mac address for all the devices on the network. The default baud rate for ms/tp on the MCU is set at bps. MCU BACnet operation The MCU serves as a BACnet gateway to a maximum of 60 diffuser control Zones. The point data is limited to diffuser master information and although slave diffusers generally mimic the master data, some detail information is not available through the BACnet point data. This includes specific diffuser setup as well as diagnostics information. The BACnet stack supports a priority array of 16 elements. Read/Write_property_multiple is supported. Segmentation is not supported. The maximum APDU size is 480 bytes. For the full MCU BACnet compliance statement please contact Rickard for the relevant document. Zone numbers allocated by the MLM Application are indicated in the BACnet application as the point identifier. For example on MCU device instance the Zone 1 control area will be indicated as Z1 on a BACnet browser. Page 9

10 This is the text string contained in the description property of the object being interrogated: In our example on Zone 1 the Diffuser with Diffuser Controller serial number has the Space Temperature and Set point parameters selected and is hence designated a master controller. The BACnet object types supported are Analog Value, Analog Output, Multi State Input, Multi State Output and Analog Input. For every object type there are 60 BACnet points available. The BACnet points are distributed as follows: Instance # Object(s) VAV Parameter Value Bacnet Device ID Device Device Object NA AV:0..59 Analog Value Space Temp C AV: Analog Value Supply Temp C AV: Analog Value Control Disk pos % AV: Analog Value Heater output % AV: Analog Value Disk Min Pos % AV: Analog Value Disk Max Pos % AV: Analog Value Heat Max % AO:0..59 Analog Outputs Setpoint C MSI:0..59 Multi State Inputs Mode See table MSI: Multi State Inputs Occupancy See table MSO:0..59 Multi State Outputs Control Override See table MSO: Multi State Outputs Occupancy Override See table AI:0..59 Analog Input Pressure Pa AI: Analog Input Flow l/s Page 10

11 A MCU Device Object with device properties is indicated below: Mapping of Data Points to a BACnet BMS As the MCU gateway can accommodate up to 60 diffusers connections, for each VAV parameter type the MCU contains 60 instance points. By default these points are arranged into 15 per channel. A BACnet browser will show these points in sequence, whether that point contains data or not. The BACnet point layout is displayed on the MCU web page. On the main page select the BACnet Point List. Page 11

12 This extract from the web page shows the BACnet point layout. The serial number display indicates the channel one and channel two data points which are active. Channel one has seven active control zones and channel two eight. Each channel has a maximum of fifteen control zones, with the inactive zones left blank. Note at the top of the web page where the user can select between C or F operation. Page 12

13 Diffuser Mode (status) multi state input 0 59 The following table contains the diffuser mode inputs. Please note these integer values are presented in decimal format on the BMS front end. The string value can be read at the state_text_property for the specific point. Decimal Value Mode Description 1 System Idle (in control temperature band) 2 Initializing 3 Heating mode 4 Cooling mode 5 Actuator in manual operate mode 6 BMS control override mode Occupancy Mode (status) multi state input The following table contains the occupancy mode inputs. These integer values are presented in decimal format on the BMS front end. The string value can be read at the state_text_property for the specific point. Decimal Value 1 Occupied 2 Unoccupied Mode Description BMS Control Override multi state output 0 59 The MLM 24 system contains some BMS commands to force certain diffuser behaviour. These commands are typically used for Zone flush or emergency operations. The following table indicates the command (decimal) values: Function Command Description Normal 1 No BMS command active Open 2 Drive Diffuser Open to pre set limit position, heater off Close 3 Drive Diffuser Close to pre set limit position, heater off Emergency 4 Emergency, this command will disable the heater output Page 13

14 Emergency Open Emergency Close 5 Disable heater output and drive diffuser completely open 6 Disable heater output and drive diffuser completely closed Backoff Active 7 Activate backoff dead band control Max Heat 8 Drive diffuser to supply air max heat position and switch heater max on Occupancy Override multi state output The following table contains occupancy override functions as set by the BMS. Decimal Value Mode Description 1 Occupancy Normal (no override from BMS) 2 Override Occupied 3 Override Unoccupied 4 Occupancy Trigger On 5 Occupancy Trigger Off Note: To enable any Control Override feature, including the occupancy override, the BMS Enable function must be set on the master controller of interest. To activate, in the MLM Application, expand the master diffuser icon, select Process/Temp Command and tick the BMS Enable box. This is a non volatile parameter. See next section on Control Override procedure. Page 14

15 Mapped MCU on a BMS Front end The following picture shows a typical MCU mapped on a BMS front end, in this case Workplace AX running on a Niagara platform showing data for zone 1. Please note the Read Only fields indicated in the Write (right hand) column. Page 15

16 MLM Control Override Handling Procedure The MLM24 system contains three internal processes for activating system control override, or back off from normal control. There is a manual control override command entered by the MLM24 Application, a Real Time Clock operation for after hours detection and an Occupancy Sense feature. Should an external BMS process such as BACnet be connected to the MLM24 system, this process will override any internal back off/override process currently in operation. Please note that these control override features are enabled per control Zone, i.e. each individual master controller unit must be activated, either by Zone specific or global commands by the MLM24 Application. The following explanation makes use of the MLM24 Application revision 7.13 or above. During the setup procedure it is assumed the MLM24 Application program is actively communicating to a field diffuser system and that the system is synchronised. Conventionally an external BMS (Building Management System) command would force a specific control override or back off action on the MLM24 system. These same control override actions can also be generated by the MLM24 internal processes and are therefore indicated under the same naming tabs. Most of the control override commands require the Diffuser controller to set the actuator and heater drivers into a manual operation mode, with the diffuser icons displayed in yellow. Manual Control Override activation The manual control override feature allows the user to enter specific control override commands by using the MLM24 Application or the MLM24 Server Application. Using the MLM24 Server Application is especially useful to command extended diffuser sections such as whole floors or buildings to perform a specific control override action with a single command. Manual control override can be commanded by accessing either a Wallstat or an On board master unit: Page 16

17 1. Expand the Wallstat or the on board master host diffuser icon in the Logical screen. On type 7 (WS) or 8 (on board) click on Process/BMS command and select the action required during control override. See the BMS Command table below. Note these flags also double as status indicators should an external BMS command be active, e.g. a BACnet BMS command received via the MCU. 2. To immediately activate a BMS command, select the Process/Temp command and select BMS Enable. The control override function selected in the BMS command tab will now be activated. 3. Note that selecting the Backoff Active box will force the diffuser to control to the dead band value contained in the Backoff band field. 4. For normal control operation again, uncheck the BMS enable box under the Process/Temp command. 5. Run the MLMServer Application to force extended diffuser areas into a BMS state. Select the BMS command tab and check the required box(es). Press Run to execute. To revert to normal operation again, uncheck the tick boxes and press run again. RTC Control override activation The MLM24 Wall thermostat (part no BT2311 5) contains a Real Time Clock used to activate a controloverride timer. This feature is not currently available on the On board master unit. To use the controloverride time feature: 1. Ensure the RTC time is correctly set. Expand the Wallstat host diffuser in the Logical screen. On type 7 (WS) click on Setup/RTC and press the read button. If the time displayed is incorrect edit the value and press write. 2. Expand the Backoff/Days tab and check the boxes where a day/night controloverride is required. 3. Where a 24 hour control override is required, typically over weekends, it can be checked under the 24H column. 4. Expand the Start time tab and enter the time required for the control override action to start. 5. Expand the End time tab and enter the time required for the control override to end. 6. Expand the Pre/Post timer tab and enter the pre and/or post timer period (in minutes) if required. A value of zero will disable the pre/post BMS command. Page 17

18 7. Expand the Pre/Post BMS Command tab and select the Pre/Post control override action required. This command will typically be used to heat/cool a building after an extended control override period. 8. Under Setup/Backoff, expand the BMS command tab. The BMS command selects the controloverride action for afterhours back off as indicated in the table above. 9. The final step is to expand the Process/Temp command tab and check the BMS Enable box. Checking this box will enable either an external BMS command or internal control override enable. Note: It is important to distinguish between the three BMS command tabs indicated. The Process/BMS tab is for selecting manual or external BMS commands. The Setup/Backoff/BMS tab is exclusively for RTC driven operations. Setup/Backoff/Pre_Post BMS tab is for RTC functions where a pre/post timer period is required. For any BMS or control override command to execute, the Temp command/bms enable flag must be enabled. If a system is required to execute a control override command after hours only, the Process/BMS command check boxes should all be cleared. RTC control override operation Once the control override start time is reached, typically after working hours, the MLM24 system will check if a pre timer period was set. If so, the pre BMS selection will be executed. In conjunction the indicator button at the bottom of the Wallstat screen will switch from WH (working hours) to AH (after hours). Once the pre timer period has lapsed or if it is set to zero, the system will execute the control override BMS selection. On conclusion the post BMS action will be activated if the post timer was set. The pre and post timer periods are implemented if there is a requirement to condition an area prior to back off or back on. Following this optional period the system will revert to normal control and the indicator will switch back from AH to WH. BMS Command Table: Function Description Open Drive Diffuser Open to pre set limit position, heater off Close Drive Diffuser Close to pre set limit position, heater off Emergency Emergency, this command will disable the heater output Emergency & Open Disable heater output and drive diffuser completely open Emergency & Close Disable heater output and drive diffuser completely closed Backoff Active Activate WH or AH dead band back off control, whichever is applicable Max Heat Drive diffuser to supply air maximum heat position and switch heater 100% on Occ Backoff Active Status flag to indicate the system is in unoccupied control mode Page 18

19 Occupancy control override control The MLM24 system makes use of PIR (Passive Infra Red) technology to detect an occupied/unoccupied state. The PIR sensors are mounted unobtrusively on the diffuser trim disk to cover the normal diffuser throw area. Optionally these sensors are also fitted to the Wall thermostat units if this is a preferred option for occupancy detection. The number of sensors mounted per control Zone is determined by the detection area, and ranges from one per control Zone to one per diffuser and Wallstat units. The sensor signals are combined in an or function, which means that detection picked up by any sensor in a control Zone will deem that Zone to be occupied. Occupancy control override operation Working Hours When the room is vacant for a specific period, the diffuser(s) in that particular Zone will drive to the minimum closed position. This period is user adjustable as delay 1 in the MLM24 Application. Should a second vacant period, as set in delay 2 elapse, the diffuser(s) will drive to the fully closed position. The factory defaults on both these timers are 15 minutes. If the room temperature drifts outside the temperature band during this state (set in the Backoff band field), the diffuser(s) will revert to the minimum closed position. If occupancy is detected during this control override operation, the diffuser(s) will revert to normal control operation. After hours After hours operation is basically the same as for working hours. Delays 1 & 2 are the same for both. The only difference is the After hours backoff band is used for phase two of the unoccupied control. The RTC operation for after hour detection is described in the RTC control override section. Note: If an On board master unit is used to control a Zone, no distinction is made between working hours and after hours and only the Backoff band parameter is applicable, as the On board master does not contain a Real Time Clock. Page 19

20 System set up for Occupancy Sense The user has the option to set the unoccupied period before the system reverts to a control override state. The following procedure needs to be followed to set the system up: Diffuser Controller 1. Ensure an Occupancy sensor is fitted to the Diffuser controller hardware or the Wallstat hardware. 2. Select the Diffuser Controller (type code 10), go to Setup menu, Occupancy present and check the Occupancy present box. By setting this parameter that particular diffuser is enabled for occupancy sense. 3. If the Wallstat unit contains an occupancy sensor it will be automatically detected by the Wallstat unit and no setup is required. Hence a Wallstat with built in occupancy sense is always enabled for that Zone. 4. All the sensors in the control Zone of interest need to be selected to be active. Note: All nodes that contain occupancy sensors will be selected as a factory default. On board master 1. Expand the diffuser icon in the Logical screen and select the On board master (type code 8). 2. Under Setup/Unoccupied delays, verify and edit the delay 1 & delay 2 periods. Note the default of 900 seconds for a 15 minute delay. 3. Check and edit the Backoff band setting. The default is 1.8 C. 4. Under Temp command, check the BMS Enable box. Page 20

21 Wallstat 1. Expand the diffuser icon in the Logical screen and select the Wallstat (type code 7). 2. Under Setup/Unoccupied delays, verify and edit the delay 1 & delay 2 periods. Note the default of 900 seconds for a 15 minute delay. 3. Check and edit the Backoff band setting. The default is 1.8 C. 4. Check and edit the Afterhours Backoff band setting. The default is 1.8 C. 5. Under Temp command, check the BMS Enable box. Note: The three parameters of interest in setting up occupancy sense are: Occupancy present as set on the Diffuser controller this enables/arms that particular sensor to be active. Unoccupied delays setting these timers to zero will stop the timers and the controller unit (Wallstat or On board) will always indicate the Zone as occupied. BMS Enable by unchecking this box, the controller unit will still show the occupied status, but will not command the Diffuser controllers into a back off state. Page 21

22 MLM24 Application Occupancy display The Wallstat and On board master units each contain an Occupied button to indicate status green for occupied and red for unoccupied. The progress bar next to the button is divided into the delay 1 and delay 2 areas. As the delay timers run down, the progress bar will decrement from right to left. Once an unoccupied condition is detected, the bar display will change from green to red. The adjacent picture indicates an On board master unit entering the second delay period, with the control disk position at the pre set minimum of 20%. Once the second delay period has expired, the control disk will move to 0% position. This position will be maintained until either: Occupancy is detected and control reverts to normal. or The room temperature drifts outside the Backoff band setting and the control disk moves back to the 20% position. Page 22