BUILDING MANAGEMENT SYSTEM CONFIGURATION AND HARDWARE

ARCHITECTURE

1. General

The BMS shall utilise the latest distributed process control technology combined with a local area network (LAN) to provide high processing integrity, high system redundancy and fast
system response time.

2. System Configuration

1. The BMS shall be configured as a distributed system of fully intelligent, peer to peer, standalone Distributed Processing Units (DPU) operating in a microprocessor based multitasking environment connected via LANs to Network Control Units (NCUs) and operator workstations.
2. NCUs shall carry out global system programming and supervisory functions only for DPUs. Where more than one NCU is required, the system shall include a minimum of three NCUs, such that failure of one NCU shall not disable global control or communications to the entire site. Such NCUs shall communicate on a dual redundant LAN in a peer to peer configuration.
   The dual LANs shall operate simultaneously and each LAN shall act as a backup to the other in the event of a single LAN failure.
3. Systems that use a PC file server to enable communications between multiple DPU LANs, shall include dual redundant servers with automatic condition monitoring and change-over in
   the event of a server failure.
4. Multiple System Workstation operators shall be able to access the system simultaneously.
5. Systems which do not provide multi-tasking, multi-user operating systems are not acceptable.

3. Response Times

Maximum response time to send signals anywhere in the network during normal operation shall be 1.0 secs.

Maximum time between update of data at the Operator Workstation shall be:

Alarm or critical points – 1 sec
Non-critical points – 5 secs

DPUs shall reset all outputs to off immediately on loss of power to the controller.

Upon power restoration the system shall provide automatic sequential restart of equipment based on current program time and program requirements without operator intervention. Plant
start-up times, taken from the time of restoration of power to the relevant MCC(s), and including for sequential start time delays, shall not exceed 5 minutes.

4. Fault Tolerance

Failure of the workstations shall not impair in any way performance of the NCUs and DPUs and shall signal to the NCUs and DPUs such failure to allow storage of alarm and change of status
(CoS) conditions for uploading to the workstations when returned to service.

Failure of a NCU or DPU shall not impair performance of the workstation in any way, beyond loss of supervision of that NCUs/DPUs system. DPU control elements are to hold to ‘last set
level’ or ‘off’ given DPU/NCU or communication failure.

COMMUNICATION NETWORK

1. Communications between the operators’ workstations, NCUs and DPUs shall be by a multi drop Local Area Network (LAN) complying with an IEEE recognised standard format suitable
   for the run lengths and environment.
2. Loss of a NCU or DPU shall not affect the ability of the remaining NCUs or network DPUs to communicate with each other or with the workstation.
3. The LAN shall be optically isolated from system hardware to prevent any induced voltage on the LAN from damaging hardware components.
4. The LAN shall be connected to function in a distributed environment, under complete control, not necessarily requiring any workstation for complete control of the process variables.
5. The LAN shall support multiple workstations functioning in a true network environment.
6. The LAN shall be capable of a LAN length of up to 1,200 metres without repeater/equaliser. A break in the communication path of the LAN shall be announced as an alarm and shall
   automatically initiate a LAN reconfiguration such that the resulting sections of the LAN continue to function as separate LANs. No loss of control shall result from such a break in the LAN. If,
   as a result of communication severance, any portion of the LAN cannot communicate with a workstation, all DPUs in the severed portion will be declared “LOST”. Upon restoration of the
   communication pathway, each returned DPU will be declared “RESTORED”.
7. Data communication on the LAN shall include error detection techniques to ensure data integrity.Error detection shall be of Cyclical Redundancy Check (CRC), Longitudinal Redundancy Check (LRC) or equivalent which has undetected error provability in the range of 10EXP-9. Error detected shall be negatively acknowledged and data shall be retransmitted.  Error correction shall not be acceptable.
8. In addition to automatic self-diagnostics, communications statistics shall be maintained. These statistics shall tabulate total communications attempted versus successful and unsuccessful
   communications by unit number. The option to reset communications statistics to zero at any time shall be provided.

DISTRIBUTED PROCESSING UNITS/NETWORK CONTROL UNITS

1.  General

NCUs and DPUs shall operate within the following environmental limits:
Temperature: Operating:
-10 to 50 degree C
Storage: -10 to 70 degree C

Humidity: Up to 95% RH (non-condensing)

The system shall utilise PROM and RAM memory.

Life safety algorithms shall be resident at DPUs on non-volatile EPROM or EEPROM, such as to minimise the risk of file corruption.
Other algorithms and parameters shall be EEPROM or RAM based for ready access for modifications and adjustments. RAM based memory shall have 72 hour battery backup.

2. DPU/NCU Power Failure

Failure/fault of any DPU on either essential or normal power supply shall be alarmed at the operator’s workstation.

After a power failure and upon a power restoration, the system shall provide automatic sequential restart of equipment based on current program time and program requirements
without operator intervention.

3. DPU/NCU Upload/Download

Each DPU/NCU shall be able to download from or upload to the PC operator workstation. Point data shall be modifiable by any authorised operator at any workstation and downloaded to the
DPU over the LAN. It shall not be necessary to enter parameters locally at the DPU for control programmes to take effect.

4. Distributed Processing Units

1. If the number of points in a particular DPU location exceeds 56, then additional DPUs shall be provided in that location. It is unacceptable to make use of the spare capacity in DPUs at other
   locations.
2. All field devices shall be connected directly to the DPUs.
3. Controllers shall consist of a removable plug-in circuit board. Products which require disconnection of wiring from the Local Controller logic card before removal shall be supplied
   with quick-disconnect type interconnection to transition to field wiring.
4. DPUs shall be microprocessor-based with all hardware, software, and operator/programmer ports. Systems shall be capable of stand-alone operation.
5. Processing Units shall be capable of a minimum of 16 universal points allowing a mix of either analog input, analog output, digital input and digital output expandable to at least 64 universal
   points.
6. The software shall provide control application packages, interface the required sensor and actuator types, and contain built-in diagnostic routines. Analogue outputs shall provide operator
   adjustable PI2 or PID control.
7. The processing unit shall have memory error checking. Upon detection of a memory error the DPU shall automatically request for a re-transmission. If the memory error remains then the
   processing unit shall halt to prevent erroneous operation. All “halts” shall report as an alarm at the control operator’s terminal and printer.
8. Software shall allow for scaling and for calibration of variations in sensor lead length to ensure display accuracy’s.
9. Each DPU shall have the ability to place I/O points in a test mode. The test mode shall allow control algorithms to be tested and developed on-line without disrupting field hardware or
   controlled environment. The treatment of I/O points in test mode shall be:

(a) Scanning and calculation of all input points shall be inhibited. Manual control to input points can be issued from any workstation.
(b) It shall be possible to control all output points but only the data base state/value shall be changed, the external field hardware is left unchanged.
(c) Control actions on output points shall be enabled but only the data base state/value shall be changed. Alternatively on-line software diagnostic tools shall be provided.

OPERATOR WORKSTATION AND ASSOCIATED EQUIPMENT

1. General

Operator Workstations shall be provided for the purpose of loading, modifying and dumping programs, setting parameters, overviewing and supervision of the building systems.

The workstations shall be used for displaying, programming, and modifying all software assignments and parameters in proper engineering units and in direct decimal value. All
program entries or modifications shall be displayed prior to execution for operator verification.
The operator, through the keyboard, shall be able to add, delete, and modify the system data file after the proper access level code is entered (minimum of five levels) through the operator’s
terminal.

The workstations shall ergonomically provide efficient operation of all console equipment by a single operator. All displays and operator controls must be easily seen and accessible to an
operator seated in a chair.

2.  Operators Workstation Hardware

The operator workstation shall consist of:

(a) 1 No. PC operating at a clock speed of at least 3.0 GHz with:

• 4.0 GB RAM memory expandable on board.
• 1 TB spare hard drive capacity after loading all software.
• DVD/CD ROM Dirive
• Modem approved by local telephone utilities supplier.
• A Super VGA graphics card capable of 1024×768 pixel resolution Minimum and 65K colours, non-interlaced (70 Hz or better vertical refresh rate).)
• 101 keyboard with 12 function keys.
• The modem capable of transmitting both voice and data at high speed in a common digital format to provide full “remote” operator’s workstation facilities.

(b) 2 No. 32″ diagonal colour graphics monitor capable of supporting SVGA graphics.

(c) 2 No. high resolution mouses.
(d) 2 No. colour printers (separate alarm and report printer) or similar with:

Supply interconnecting data cables, power cords and surge-suppressing (fused) power strips, as required for a complete Work Station installation.

Provide a UPS with 4hr capacity to back up the workstation and periferals.

3.  Portable Lap Top PC/Hand Held Tool

1. To assist owner’s personnel in troubleshooting the mechanical systems, connections for Portable Lap Top PCs and Hand Held Tools shall be provided at each NCU and DPU.
2. Connection of the Portable Lap Top PC and/or Hand Held Tool shall not affect the normal operation of any other parts of the system.
3. The password used to gain access into the system using the Portable Lap Top PC/Hand Held Tool shall be the same as the password used to log on to the Operator Workstation.
4. The method of addressing points used at the Portable Lap Top PC/Hand Held Tool shall be the same as the method of addressing points at the Operator Workstation.
5. The method of accessing data stored in any one NCU or DPU shall be identical to the format for information stored in other NCUs or DPUs.
6. The Portable Lap Top PC/Hand Held Tool shall provide the following functions for all points in the network:

• Displaying point status.
• Adjusting analogue values.
• Commanding binary values.
• Viewing last 48 samples for all analogue values.
• Viewing last 10 change of states for all binary values.
• View and adjust alarm/warning limits.
• View and adjust time schedules.
• Six Hand Held Tools shall be provided
• Portable Lap Top PCs shall not be provided.

4.  Automatic Paging System (APS)

The BMS shall have facility for the addition of automatic pagers such that any of 10 (ten) designated alphanumeric, local utility supplier approved pagers will be called when selected urgent alarms are activated. This facility shall allow such alarms to be annunciated and acknowledged through any touch-tone telephone compatible with android phone and iPhone.

It shall further allow dialogue between man and machine through the touch tone telephone in the form of synthesised voice output and keypad input to perform and not limited to the
followings:

(a) Change setpoints.
(b) Change schedules.
(c) Request status.
(d) Determine condition of equipment.
(e) Report alarm condition.

5. Leased Line Connection to Remote Sites

• Facility for leased line connections shall be provided such that the BMS shall be able to communicate with other remote sites as directed by the Employer.
• The leased line connection shall be directly connected to the LAN without being connected to any PC or workstation. The intent of this is to ensure continued survivability of the communications between sites without the requirement of any PC or workstation.
• The system shall similarly be capable of supporting connection to remote sites through the public switching telephone network. The telephone connection shall also be connected directly
  to the LAN without being connected to any PC or workstation. Communications rate shall be as approved by the local Telecommunications Provider.
• Connection between remote sites may be initiated from any site. There should be no designation of any one specific site to initiate dial-up.

6. Network Control Units (NCU)

• All data shall be continuously collected and processed. Each NCU shall have enough buffer memory to store all events during any communication breakdown between the NCU and the CPU under the normal expected number of breakdown events.
• The transmission protocol of NC shall be compatible with the CPU.
• Each NC shall have a self-diagnostic routine to monitor any fault in the NC and report the fault, if any, to the CPU in the control room.
• The NCU should be able to run on its own independently of the main computer during the later breakdown.
• Provision of restarting BMS system and updating of system status by NCUs.