Remote Telemetry System Theory of Operation

Remote Telemetry System Theory of Operation The Dexter Fortson Associates, Inc. (DFA) Remote Telemetry System is a complete system package comprised of the following groups: System Control Computer (SCC), Remote Terminal Units (RTU) and if needed Repeater Units (RU). The following pages provide a group overview followed by a detailed description of the system groups. A current model Dell OptiPlex GX series, Pentium PC style computer, with DFA system software controlling one or more of the following I/O groups: • • • • • Radio Modem connected to a VHF, UHF, Trunked or ‘Spread Spectrum’ Radio Data Modem with Dialup or Private Line phone service Carrier Current Modem with 120vAC Interface Data Interface (RS-232) or Fiber Optic (62.5/125) or Wire Line (RS-422/485) Voice Modem with Radio, Cellular or Dialup phone service System Control Computer.  Included with the SCC is a logging printer and a Uninterruptable Power Supply (UPS). DFA provided graphical interface software runs on a Windows XP Professional Operating System platform and works in either or both ofthe following modes: Data Collection - periodically the system interrogates each remote unit (RTU) and records the necessary data in a ‘fixed length ASCII’ or ‘dbf Format’ file. Network (LAN) accessability is an option. Exception reports are custom generated as necessary. Monitor & Control - displays status of all points and allows control of each point via keyboard or mouse. Periodic polling insures all RTU's are still active. Logic algorithms are built into the software with variables setable by the chief operator with optional password protection. Custom software and screen display upgrades are available through DFA at the current software rate. Unlike most other control protocols, DFA designed its protocol to allow multiple SCC’s and unsolicited messaging. The communications channel is continually monitored to accept any alarm or unsolicited messages sent by the remote units [RTUs]. Should operator notification or intervention be required, due to alarms or problems, the system will: • • • Display a 'Alarm Window' on the SVGA Monitor. Record date, time and reported problem on the printer. Require operator acknowledgment within (x) minutes, or: Dial a Digital Beeper with a displayed location and alarm code; and/or Dial a phone number list with a synthesized voice message; and/or Transmit via radio link a synthesized voice message; Dexter Fortson Associates, Inc. Page 1 and Accept DTMF instructions keyed in from the telephone or radio. The System Control Computer communicates with the Remote Terminal Units and/or Repeater Units. Remote Terminal Units. These units, 'collect, store and forward' information, and/or 'monitor and control' remote devices. Inputs may be Digital, Counter(16 or 32 bit), Analog, or Position Encoder. Input signal requirements are: Digital or Counter..Dry Contact / 120v AC-DC / 24v AC / 12v DC Analog..............4 - 20mA sinking / 0 - 5vdc Encoder.............2 channel quadrature with Index and Home Outputs may be Digital or Analog. Output signals provide: Digital......Dry Contact (1A @ 120v AC-DC) Analog.......4 - 20 mA (Sourcing or Sinking) or 0 - 5v dc Many types of RTU's are available: Expandable, Midi, Mini, Area, PLC and Custom. Expandable RTU [E-RTU] utilizes a card cage design allowing any combination of Input / Output cards required by the customer’s installation. Group 1 E-RTU's have 5 I/O slots available. Group 2 E-RTU's have 12 I/O slots available. For a detailed list of the PC Cards currently available see the following sections in this book. Program Space 32k SRAM / 32k EPROM / RTC Midi-RTU 8 4 8 8 1 Mini-RTU 4 2 4 4 1 [D-RTU] has a fixed I/O set. Digital Inputs (120vAC / 24vAC / 12vDC through a Relay Input PCB) Counter Input (Dry Contact to DC Power) Analog Inputs (4-20mA sinking, may be jumpered as Digital Inputs) Relay Drives (through a Relay Output PCB) Analog Output (4-20mA / 0-5v) Program Space 32k SRAM / 32k EPROM / RTC [M-RTU] is physically smaller and has a fixed I/O set. Digital Inputs (120vAC / 24vAC / 12vDC through a Relay I/O PCB) Counter Input (Dry Contact to DC Power) Analog Inputs (4-20mA sinking, may be adapted as Digital Inputs) Digital Outputs (Dry Contact through a Relay I/O PCB) Analog Output (0-5v) Program Space 2k SRAM / 8k OTP-ROM Area-RTU [A-RTU] is a stand-alone, programmable cluster controller for up to 8 x-RTUs. The A-RTU uses a card cage design, allowing any of the E-RTU boards to be used. An LCD Display and Keypad are used for data monitoring and control loop programming. Programmable Logic Controller-RTU [PLC-RTU] are protocol converters, translating PLC information to DFA data packets for SCC use. Check with the DFA manufacturing center for current protocols supported. Custom-RTU A whole range of custom RTU designs are under development or on the shelf. Consult the DFA manufacturing center for detailed information. All RTU's may be AC or DC powered. The Mini-RTU may be Solar powered. Dexter Fortson Associates, Inc. Page 2 If a group of RTUs is too far away for the System Control Computer to converse with directly, then use a Repeater Unit is used. Repeater Unit. This unit is used to relay the messages outbound and inbound on each 'Radial’ leg. Up to 16 Repeater Units may be on each Radial leg with up to 8 Radials possible, (Star burst pattern). Up to 250 RTUs may be serviced directly by each RU. A RU may be AC or DC powered. Solar powering is possible if traffic flow is low. Two Repeater types exist, Store & Forward and Dual Frequency. For systems utilizing dual frequency repeaters, (two radios), a Repeater Board (P/N 0592) may be added to a Remote Telemetry Unit making it a combined RTU-Repeater. Combinations of Radio, Cellular or Wired Telephone, and Carrier interconnections are possible to meet the customer’s specific needs. System options available include: Current • • • • Master / slave control shift via Data Modem or Radio. Remote monitoring and after hours control via Auto Answer Data modem. Voice reporting over the phone system or voice radio channel. Remote system control (Limited) via Touch-Tone Phonepad. SYSTEM EXAMPLES Mini-RTU Tank Level (solar power only) Remote Valve Midi-RTU Lift Station Multi Pump Station Irrigation Control Expandable-RTU Process Control Lift Station Multi Pump Station Voice Dialer Process Control Irrigation Control Custom Applications Power Factor Controller Custom-RTU Programmable Logic Controller RTU Custom Applications Dexter Fortson Associates, Inc. Page 3 System Range and Timing Using sixteen Repeater Units per System Radial, assuming 10 mile spacing between Repeaters, a Radio Telemetry System could cover a 340 mile diameter circle, (170 miles per Radial). Using 1200 Baud Data Modems and the dial-up telephone system, (AT&T, MCI, etc.) for all or part of the system, a Telemetry System could cover any distance, including direct dial international service. As each query and response message pair takes .032 seconds (FO, wire line or Carrier Current) to 1.1 seconds (radio), customer response time requirements must be considered in determining the number of System Control Computer Interfaces, Radio Frequencies required, Fiber Optic or Telco Data Lines needed, etc. For example, a fully loaded system with 1 CPU and 32,250 RTUs being reached through 8 Radials with 16 Store & Forward RUs per Radial, using ONE radio frequency and low speed, would require 89 hours to interrogate all units. Using Dual Frequency RUs the time would be 9.9 hours. Using FO or wire line and high speed the time would be 16.8 minutes. [Presuming No unsolicited (alarm) messages happen and all messages are 'short' block.] These examples represent a 'system maximum' calculated worst case condition and would NOT be customer viable!! In the above example, multiple communications channels would be required to decrease the loop response time to a acceptable time frame. DFA custom engineers each system to minimize 'control loop' time based on the following: Number of RTUs Control, Data Collection or Mixed system Number and type of Repeater Units Minimum acceptable response time Our detailed discussion will begin with the central controller, referred to as the MACS Host System. Dexter Fortson Associates, Inc. Page 4 MACS System Control Computer The DFA Host system (System Control Computer)is designed as a modular package to facilitate troubleshooting, service and maximize up-time. Any module may be repaired or replaced without effecting the other modules. Field upgrades are easier and usually do not require a site call by a programmer or technician. The heart of the MACS Host System is the system control computer. DFA uses  Dell OptiPlex GX series PC. Specifications for the PC will be at a minimum or the latest available, a PIV 3.2 GHz System with 512M RAM and at least 40GB  Hard Drive running Windows XP Professional Operating System. The High Speed Data Modem and remote access software is included to allow DFA programmers to test and upgrade the customers system without requiring a site call. With the correct software it can be used to call Digital Beepers to report Alarm conditions. The uninterruptible power supply (UPS) provides backup power for the computer and monitor and line filtering for the printer. The Radio Modem cabinet located near the SCC has its’ own internal backup system as a optional feature. Dexter Fortson Associates, Inc. Page 5 System Control Computer The system requires a Pentium AT style (100% IBM Compatible) computer with at least 512MB RAM, a 1.44MB Floppy Disk, a 40GB Hard Disk and a CD-ROM;  utilizing Windows XP Professional operating system with a SVGA monitor with at least 16M video RAM. The system will be equipped with 4 COM ports for connection to any of the following sub-systems: Base Station Radio, (2 - 40 watts), on the FCC assigned frequency and a DFA Radio Modem (600-1200B). RS-485 Interface over 2-wire twisted pair (19.2kB). Fiber Optic Interface over duplex fiber cable(19.2kB). High Speed Data Modem over a phone line (14.4kB or better). The computer talks to the peripheral equipment through some or all of the following ports: Data Modem COM1 (for Remote Control and Diagnostics) Mouse COM2 (for O/S and DFA graphical interface software) Main I/O COM3 (Radio Modem/RS-485/Fiber Optic/etc.) Voice Dialer COM4 (Dials phone numbers and Watchdogs the CPU) Printer LPT1 Cabling is 'PC' standard, (9 pin and 25 pin connectors). Utilizing DFA graphical interface software, the computer will Automatically (at preset intervals), or at the operators' request, initiate a polling sequence to one or more RTUs, requesting each On Line remote telemetry unit to turn ON, OFF or change value on selected outputs, or answer with its' collected data. For a Data Collection System, this data is stored in the computer until all stations have answered or have been repolled the preset number of times. At the end of the polling sequence, using a Gas Delivery System as an example, all flow information is time hack corrected; temperature and pressure corrected, as needed. Compared with the previous periods' data; percent variance calculated; cubic feet of flow calculated; and a final polling report printed, to include a list of Off Line and No Answer stations. At this time an optional network file may be created for uploading across a 'Local or Wide Area Network.' A Delivery RTU would have some or all of the following boards: AC Line Board with power supply or Solar Power Option µController board with appropriate software Analog Input board Temperature board Pressure board Counter board Prescaler board Digital Input board Shaft Encoder board For a Monitor & Control System, each remote will 'check-in' with the System Control Computer at preset intervals. Should one or more monitored 'points' change state at a RTU, it will call the System Control Computer immediately. 'Loss-of-Power' or 'Tamper' will also initiate a call. The RTU will keep calling until answered. When the System Control Computer polls an RTU, it Dexter Fortson Associates, Inc. Page 6 acknowledges with its status. DFA graphic displays using "point and click" are available to ease the operator interface. A Monitor and Control RTU would have some or all of the following boards: AC Line Board or Solar Power option µController board with appropriate software Analog Input board Temperature board Pressure board Analog Output board Digital Input board Digital Output board Shaft Encoder board Serial Interface board Data Logger board A vehicle mounted controller is available for mobile monitoring and control, or testing, of RTUs. The System Control Computer (SCC) operational sequence for a Radio Network is as follows: Transmit Computer brings up 'Request to Send' (RTS) Radio Modem converts this to 'Push to Talk' (PTT) Radio begins transmitting carrier tone (CCITT V.23) Radio Modem returns 'Clear to Send' (CTS) to computer after approx. ≅300msec Computer outputs unit address, then data, then CRC Computer brings down RTS Radio Modem brings down CTS Radio Modem waits until data has been transmitted then brings down PTT Receive Radio sees 'RF Carrier' Radio Modem sees carrier signal from radio Radio Modem delays until carrier is stable (≅300msec) Computer sees 'Carrier Detect' come up (RLSD) from Modem Computer checks incoming data for correct CRC error code and Address If correct, computer records data from remote unit If incorrect or no RLSD within 5 seconds computer repolls Computer starts over with the next On Line address The Radio Modem includes a 10 second maximum transmit time timer, should the computer develop trouble during transmission. Once time-out occurs, the EIARTS lead must be turned OFF to reset this timer. Output control messages are sent to the control mode RTUs as needed, and acknowledged. The System Control Computer will poll the control mode RTUs at predefined intervals to insure system integrity. Dexter Fortson Associates, Inc. Page 7 Remote Terminal Unit The boards of the RTU can be divided into four groups: Power, Control, Input and Output. We will discuss them in order. The RTU is normally enclosed in a NEMA 12 steel enclosure. NEMA 4 or 4X(SS) enclosures are options available. POWER GROUP The Power group is composed of the AC Line board & Power Supply, and optionally the Battery Option (internal), and the Solar Option (external). Two power modes are available for the RTU, AC and DC. AC - 117 volts AC 60 Hz input with optional battery backup for up to 24 hours of AC outage. Battery charger included. DC - 14-24 vDC system with battery charger and optional solar charging. LINE BOARD (P/N 0675) The AC Line board (P/N 0675) has the AC input fuse [2A] and ‘Main Power’ switch on the lower section of the board. An 'AC Good' indicator lights when the AC is present. The upper section of the board is 15 volts DC input and charge control. A ‘DC-OK’ LED is provided for troubleshooting. The Battery and the Radio connect to this printed circuit board. Two types of System Power are provided: Battery backed and AC derived for I/O use. On the DC connector: B = Battery R = Radio Bp = Battery backed System Power S or P = Non Battery Backed System Power (when AC fails this does too) AC to DC conversion is handled by the Switching Power Supply behind the Line board. For complete system shutdown, turn OFF the Power switch and remove the DC connector. BATTERY / SOLAR POWER OPTION These options are sized for the specific application. Battery requirements depend on the type and number of printed circuit boards in the RTU, as well as remote power requirements - i.e., Prescaler boards, 4 - 20 mA loop devices, etc. The Solar Option is composed of one or more solar panels, (depending on charging requirements), the Solar Control module and the selected Battery. Each 1.5'x 3.5' solar panel will provide 14v at 3A on a sunny day. DFA will recommend the number or panels required for each RTU installation. Panel mounting brackets, for pole or roof mount, are supplied with the purchase of a complete Solar Option. A new addition is a regulated Loop Driver Board for 4-20mA transducers that require a fixed voltage. This board outputs 15vDC at up to 100mA with a 7 to 18vDC input. This board is required, and included, in Solar applications. Dexter Fortson Associates, Inc. Page 8 CONTROL GROUP The Control group is the µController board and the Radio. µCONTROLLER BOARD The µController board monitors data received from the radio, through a V.23 modem, looking for its unit address. When it sees its' group and address, it waits until carrier stops; then grounds PTT, waits .2 seconds, then starts transmitting. Internally the board outputs an address to the Mother board, reads the data bus, increments the address register and starts over. The µ Controller (microController) board (P/N 0575 or 0576) utilizes an Intel MAC-96 family microController IC. The 0575 board has 8k OTP-ROM with optional 2k SRAM; the 0576 board has 32k EPROM and optionally 32K SRAM with a Real Time Clock. A µController transmitted data stream example is as follows: Group Address 00 Unit Address Control Byte Counter 1 MSB Counter 1 LSB [Up to 8 Frames of] Counter 2 MSB [8 Bytes per Frame] Counter 2 LSB Analog Ch1 Analog Ch2 Analog Ch3 CRC FF/FF (as necessary) The µController board converts the data stream from parallel to serial ASCII data and then converts it to either frequency shift keyed (FSK) analog signals through a CCITT V.23 Modem, or RS-232 EIA signal levels. Available FSK speeds are 600 or 1200 Baud. RS-232 speeds are 300 to 19200 Baud. The frequency shift keyed (FSK) data is sent to the radio via the P2 connector on the board. RS-232 signals are via the P1 connector. A 12 second transmit 'time limit' is imposed on P2 connector to protect the radio. A push button on the µ controller board is for manual transmit. The board will output a complete message for each push of the button. Holding the button depressed for 2 seconds will reset all the CPU registers. NOTE: The RS-232 interface and the Radio Modem interface may not be used simultaneously. The System Control Computer software will record any Alarm occurrence. A Position Encoder board (P/N 0727) may be added to the µController board for Pivot operation. RADIO Most any radio capable of 'flat audio in / out, Push To Talk and Carrier present signaling' could be used with the RTU. DFA’s standard radio offerings, depending on application, are the Data Net radio (2-4 watts VHF / UHF w/o PL)and Motorola CM200 Radius radio(10-25 watts VHF / UHF w/ PL). The Radio Interface cable, (from 6 pin Terminal Block to Radio), will change depending on the radio selected. The Radio Interface pinout is as follows: Transmit Signal Receive Signal Push To Talk Carrier detected (.150mv (.300mv (Ground (Jumper analog)flat analog)flat = Transmit) selectable) Dexter Fortson Associates, Inc. Page 9 +DC Power Ground The +DC power and Ground leads will be a separate fused cable on radios greater then 5 watts. Carrier signal polarity is selectable on the µController Boards. Motorola Radius radio must be custom programmed by DFA as to operation and Expanded Interface options. A 'Radio Remote Option' is available should the radio need to be remotely located, (1000 feet maximum) from the RTU. This option requires a Fiber Optic cable of two twisted pairs be run to control the radio. A 'Solar Power Option' Kit with battery may be used to power the remote (radio) end of this option, if AC is not available. If 2 pair cable is used two RTUs can utilize the same remote end radio. INPUT GROUP Digital Input, Counter with or without Prescaler boards), Analog Input with or without Transducer boards), Shaft Encoder Input, Relay Input and Field Wiring boards are part of this group. DIGITAL BOARD (P/N 0520) The Digital board (P/N 0520) has eight bits of optoisolated input. Each input is referenced to a common pin in groups of four. The common pin is intended to be at or near ground. Input voltage range is resistor selectable and must be specified at time of ordering. No storage of information exists on the board. The condition of the eight inputs at the time the board is addressed by the µController Board is the data byte forwarded to the controller. Each input has a LED, which is 'ON' for a logic 1. Boards built for 117AC require a minimum of 45v to turn 'ON.' Board addressing is via the DIP switch, with the MSB switch closest to the Voltage Regulator. Switch CLOSED is Logic '0.' Refer to the System Memory Map for specific addressing. COUNTER 32 BOARD The Counter 32 board (P/N 0510 or 0511) is similar to the Counter 16 board, but will only operate with the µController board. The Counter 32 board has 4 or 8 counter IC's installed and can be configured as follows: One 32 bit Counter or Two 16 bit Counters One 32 bit Counter and Two 16 bit Counters or Two 32 bit Counters or Four 16 bit Counters (4 IC's) (8 IC's) Dry Contact inputs to the board are Form X or Y contacts. Debounce timing is jumper selectable, (Jumper T), with three choices. Jumpers 'A' and 'B' defines 16 or 32 bit mode. Revision A boards - Board addressing is via the DIP switch positions' 3-7 with positions 1 and 2 used to recognize 4 or 8 Counter IC's installed. Resetting the counter groups is via pads next to the terminal block marked 'RA' and 'RB'; grounding either of these points will reset counter group 'A' or 'B' depending. Revision B boards - Two extra Jumpers are added near the DIP switch. These select Read mode for the counter data, (i.e., read from MSB to LSB or LSB to MSB in 16 or 32 bit mode). Reset for both counters is via the push button below the terminal strip. Dexter Fortson Associates, Inc. Page 10 PRESCALER BOARD The Counter board may be used with a Prescaler board between it and any contacts, Magnetic Pickup Units (MPU's), or similar. There are three styles of the Prescaler board: P/N 0550 Rev A = Amplifier with divisor to 2 billion Rev B = Amplifier with divisor to 16K (Current Production) P/N 0552 Totalizing = Adjustable Amplifier MPU Calibrator (000.01 to Digital Display Totalizer Output pulse rate divided Battery backup (6 months) 999.99) (optional) by 100/500/1K to system power The Prescaler has a divisor switch and an amplifier setting and provides 'system ground' pulse output to the Counter board. ANALOG BOARD The Analog board (P/N 0525 or 0526) provide up to eight sinking analog inputs to an A to D Converter addressed by the µController board. Two groups of Analog boards are manufactured: Group 1 has 4 inputs and Group 2 has 8 inputs. Each input has a 'Zero' and 'Span' adjust and will accept: 4 - 20 mA, 0 - 5 VDC, or +/- VDC. Conversion is 8 bit and is made as the board is addressed. There is no memory on the board. Each Analog board takes up 8 addresses and is addressed as follows: J2 = A7 or A7\ = Group Address (select one) J1 = A6 - A5 - A4 = Board Address (select one) A3 - A2 - A1 = Channel Conversion Address J3 = READ\ or Ground (µController board dependent) The switch on the edge of the board controls DC power to the board, shut off (push down) before removing board from the Card Cage. TRANSDUCER BOARDS There are three Transducer boards that can work with the Analog board. Temperature Transducer board (P.N. 0660) interfaces a 3-wire RTD to a 4-20mA Loop. Temperature Transducer board (P.N. 0665) interfaces a 2-wire Solid State Temperature Detector to a 4-20mA Loop. The Pressure Transducer board (P.N. 0560) interfaces Strain Gage type pressure transducers to a 4-20mA Loop. SHAFT ENCODER BOARD (P/N 0540) This board inputs from a 2 channel shaft encoder. The board uses an Index, (once per revolution), and a Home Switch for multiple turn applications. Inputs are optoisolated and low current controlled, (<5mA). The board also contains a 8 output relay driver section, using DC relays, that replaces a separate Digital Output board. There are no required adjustments on the board. The board uses two addresses in the I/O map for the Encoder, (low byte - high byte), and one address for the Relay Driver, (same as the #1 DO board). Addressing is via a Programmable Logic Array chip and is factory set. FIELD WIRING Field Wiring / Digital Board (P.N. 0655) This board has 16 input / output lines protected by MOV's and is intended for use with the Digital Input, Output Boards and the Analog 8 channel Input Dexter Fortson Associates, Inc. Page 11 board. There are four, (two groups of two), fused power lines and four low side common tie points, that are system ground. The latest revision includes a +15v DC isolated/regulated power supply for Analog Loop devices. RTU Input / Output (I/O) EXAMPLES Counter Inputs, Encoder Inputs, Analog Inputs and Analog Outputs are via the Field Wiring board Rev.’D’ and are protected by 46v MOV’s. Subtle changes exist in the Analog input circuits depending on board revision. Some new boards will have jumpers to convert a Ai to voltage measurement rather then current. DC Power and Common are available at the Field Wiring board ‘center connectors.’ The lower four terminals are DC Power Common, (direct to backpanel). The upper terminals are: top two DC power unregulated, (+P / ≅ 20v); bottom two are DC power battery backed, (+BP / 13.8v). Dexter Fortson Associates, Inc. Page 12 INPUT EXAMPLES Use the figures at left Counter Input With customer supplied dry contacts, counting inputs are commoned to +Power or +Battery Power on the Field Wiring board. Use the supplied I/O Labels (inside door of RTU), or RTU Worksheet for your site to determine the specific input terminal connection points on the Field Wiring board. Counter inputs must use DFA supplied power, as they are ‘optoisolated’ and ‘debounced’ on the next board in from the Field Wiring board (Counter board / Compact I/O board / Expanded I/O board) Analog Input DFA analog inputs are the Sinking type. Within DFA’s boards the inputs are commoned to DC Ground. Any current device used must be of the Sourcing type, (device references DC power). The example at left is for a two wire device; three wire devices can be connected if they Source current. Optionally a isolated regulated power supply is available should the installation require it due to loop distance or ‘type of power’ conversion. Switch Inputs Customer supplied dry contacts are interconnected to the Relay Input board (P/N 0670). Should dry contacts not be available, the current production (Rev C) boards are jumper selectable, on a per channel basis, for two input voltages; 120v AC / DC or 24v AC or 12v DC. Shunt headers may be special ordered for other voltages; i.e. 24 v DC or 50 v DC. +12v DC is available on the Field Wiring board at point +BP; 120v AC is available on the Line board at the .250 Fast-On tabs next to the Transformer. Each channel of input requires 16mA to operate. OUTPUT GROUP The output group consists of a Digital Output board, an Analog Output board, Relay Output board, and part of the Encoder board. DIGITAL OUTPUT BOARD (P/N 0515) The Digital Output board (P/N 0515) provides eight dry contact NO outputs rated at 1 Amp at 250vDC maximum. The output interface is two sets of four relays to a common power rail. Each output has a 1A Pico fuse for circuit protection, (socketed, NOT soldered). Each group of four may have different power supplied. The board is addressed by the µController at least once every second (approx.) to retain any 'closed' contacts. Should the RTU system 'lockup' any energized relays will be de-energized after approximately 2 seconds. The board is addressed by SW2, (occupying one address on the buss), and works only with the µController board. ANALOG OUTPUT BOARD (P/N 0535 Rev B) The Analog Output board (P/N 0535 Rev A) uses a quad D to A converter to provide four Sinking type analog signals to outside devices. Each output can be individually set to one of the following types: 4 to 20 mA. 0 to 5 volts DC Rev B boards have a different output section. This revision allows Sinking or Sourcing connection to each channel as well as adding 0 to 20 mA output. Rev B is the current production board. Dexter Fortson Associates, Inc. Page 13 Each output has a 'Zero' and a 'Span' adjustment for calibration. The board occupies four addresses on the bus and can be set to any four address boundaries. Switches 7 through 2 correspond to A7 through A2. This board may only be written to (not read from) and only works with the µController Board. ENCODER BOARD (P/N 0540) The Encoder board (P/N 0540) contains a Relay Drive section capable of driving 8 General Purpose DC or Solid State Relays. The outputs are optoisolated and are addressed as Digital Output board #1. Eight LEDs are on the logic side of the board to show which outputs are latched ON. Board addressing is via a PLA chip and is factory set. RELAY OUTPUT BOARD (P/N 0672) The Relay Output board (P/N 0672) provides eight Dry Contacts for customer use. Each contact is rated at 5 amps - 24 v DC to 120 v AC. This board is usually used with the Expanded I/O board or when the Digital Output board relays will not suffice. LEDs next to each relay show when the relay is energized. Dexter Fortson Associates, Inc. Page 14 COMBINATION A Compact I/O board (P/N 0530) is used in the Mini-RTU to provide the required inputs and outputs needed. This board, when completely stuffed, has: 4 - Analog Inputs (4-20mA sinking type) 4 - Digital Inputs (use Dry Contact to Ground) 2 - Counter Inputs (use Dry Contact to Ground) 4 - Digital Outputs (Dry Contact to a Common Rail) 1 - Special Purpose Output (Digital / PWM / Analog = 0-5v) This board mounts to a µController board (P.N. 0575) via the two picket fence connectors. Compact I/O Rev. B and above works with the 0576 board. A card cage is not required. Power is brought to the µController board via the card edge connector. This board set is used in the Solar-RTU as well as the MiniRTU. SOLAR RTU µController board Compact I/O board Field Wiring-D board Solar Control module Solar Assembly Batteries (30AH Min.) Enclosure (NEMA 4) MINI RTU µController board Compact I/O board Field Wiring-D board Line board (if AC powered) Batteries (optional) Enclosure (varies) A RTU I/O board (P.N. 0532) is used with the µController III board (P.N. 0576) in the Midi-RTU to provide the following I/O points: 8 8 4 8 1 Digital Inputs Analog Inputs Counter Inputs Relay Drive Outputs Analog Output (Dry Contact to DC Power) (4-20mA sinking / or 0-5v) (Dry Contact to DC Power) (Ground Switched with Diodes to 12vDC) (4-20mA sinking or sourcing / 0-5v adjustable) Other connectors on this board provide Status LED's, Alphanumeric or Graphic Display driver and a 20 key keypad input. Various mini-boards are available for the Mini-RTU and the Midi-RTU to expand the functionality without requiring the step up to a Expandable-RTU. Dexter Fortson Associates, Inc. Page 15 REPEATER A Repeater Unit passes messages from the System Control Computer (SCC) to RTUs or the next Repeater Unit and vice versa. A Store and Forward RU incorporates a different setup than a RTU. It has a µController board and a DC Line board. Radios can be 5 to 40 watts, as required and licensed. Extra power supplies may also be necessary. If a 5 watt or less radio is used, the Solar Power Option with batteries may be used to power the RU, provided message count (traffic flow) is low enough. The Dual Frequency Repeater board (P.N. 0592) fits between a RTU and two radios. Omni directional antennas are generally used for repeaters, Yagi's are possible. DFA engineers each repeater system on a 'specific customer requirement' basis. Utilizing the µController board (P.N. 0576) a repeater network would be set up using the Group Address Byte as follows: Group Address High Nibble = 0 Group Address Low Nibble = 0 Unit Address = 1 4,000 = Local Station to 15 = Group Address to 250 = (RTUs) possible RTUs Group Address High Nibble = 1 to 8 = Repeater Radial Group Address Low Nibble = 0 to 15 = Repeater on Radial Unit Address = 1 to 250 = (RTUs) 32,250 possible RTU's A 'Local message', System Control Computer to RTU, would be six bytes long and look like this: Group Address / 00 / Unit Address / Station Control Byte / CRC / CRC A 'Repeater message', System Control Computer to Repeater to Repeater to RTU, would be six bytes long and look like this: First Repeater Address / Repeater Control Byte / Unit Address / Station Control Byte / CRC / CRC The System Control Computer could attempt a 'Local Message' transmit to any RTU, thereby bypassing the Repeater, with a six byte message starting with the Group Address, followed by '00' in the second byte. A six byte Repeater message has the first repeater address on that radial (x0) as the first byte; followed by the Repeater Control Byte, containing a control nibble (upper nibble) and the destination repeater address (lower nibble); followed by the Unit address; then the Station Control Byte. As the message is 'repeatered' out the radial the first address is incremented once for each retransmission. The 'Unit Repeater' would see the lower nibbles of the first two bytes of a received message being equal. It would then convert the message to a six byte message looking the same as a 'local message' with the Unit Repeater address becoming the Group Address. See the diagram on the previous page. Dexter Fortson Associates, Inc. Page 16 GENERAL NOTES REQUIRED TOOLS • • • • • • • • Screwdrivers - Slotted Screwdrivers - Phillips Nut Driver - 1/4 inch Hex Driver Set Diagonal Cutters Needle nose Pliers Meter - Fluke DMM-75 or equal Function Generator - 1 to 100k Hz Calibrated Current Source - (4 to 20mA dc) Soldering Iron - Temp. controlled, fine point Desoldering tool Solder - 60/40 Rosin core Extender Card (from DFA) Counter Bd. Tester (from DFA) Field Test Unit (from DFA) - These items are NOT necessary for general field troubleshooting. When working must be shut values, etc. Boards, just OFF. on the AC Line board or the µController board, the entire unit down resulting in loss of all counter counts, output latches, When working on the Counter, Digital, Relay / Encoder, or Analog the board being removed from the Card Cage needs to be turned NOTE: In later Revision boards the Power Switch has been removed - just pull out the Board. Turning OFF the AC Power switch on the Line board does not remove the Card Cage, or in a Mini / Midi-RTU from the µController board. Battery Option is still supplying DC power to the electronics. To depower the RTU, remove the battery connection as well as turning Power. power from The backup completely OFF the AC Dexter Fortson Associates, Inc. Page 17 AC Line Board P/N 0600 Rev. D ALL ADJUSTMENTS REQUIRE A CALIBRATED DMM FLOAT VOLTAGE ADJUSTMENT 1. 2. 3. 4. 5. Disconnect battery from DC Terminal Block ‘B’. Connect DMM between TB ‘G’ [-] and TB ‘B’ [+]. Power up the system. Adjust pot ‘V’ until meter reads 13.8 VDC. Reconnect Battery. CUT-OFF VOLTAGE ADJUSTMENT 1. Remove Battery from DC Terminal Block ‘B’. 2. Connect DMM to TB ‘G’[-] and TB ‘B’ [+]. 3. Adjust pot ‘V’ downward until relay drops out. [DMM goes to 0v.] Record voltage. 4. Adjust pot ‘CO’ as required to achieve relay dropout at 10.0 volt. Repeat step 3 as required. 5. Remake ‘Float Voltage Adjustment’. 6. Reconnect Battery. Dexter Fortson Associates, Inc. Page 18 µController Board P/N 0575 & 0576 ALL ADJUSTMENTS ON THIS BOARD REQUIRE A OSCILLOSCOPE TRANSMIT LEVEL 1. 2. 3. 4. 5. 6. 7. Place µController board on Extender Card. Place O-Scope probe on P2-1. Power up the system. Press 'Manual Transmit' Push Button. Observe 'Peak to Peak' voltage on scope. Adjust R20 (X) for .15 VAC P-P with NO clipping. Remove power, remove probe, reinstall board. RECEIVE LEVEL 1. 2. 3. 4. 5. 6. 7. 8. Place µController board on Extender Card Place O-Scope probe on U4-4 Jumper P2-1 to P2-2. Power up the system. Press 'Manual Transmit' Push Button. Observe 'Peak to Peak' voltage on scope. Adjust R19 (R) for .3 VAC P-P with NO clipping. Remove power, remove jumper, remove probe, reinstall board. The signal The above adjustments are the same for all µController Boards. locations will differ. Dexter Fortson Associates, Inc. Page 19 Analog Input Board P/N 0525 Rev. B ALL ANALOG INPUT ADJUSTMENTS REQUIRE A CALIBRATED CURRENT SOURCE AND A CALIBRATED DIGITAL MULTIMETER (DMM) ZERO Adjustment 1. 2. 3. 4. 5. 6. 7. 8. Place Analog board on Extender board. Adjust current source to 4mA output. Connect source to input channel under test. Place DMM on A to D input pin for the same channel. Power up the board. Adjust 'Zero' Pot. until DMM reads 0.00 VDC. Check the 'Span' adjustment if 'Zero' was changed. Turn OFF board, remove Extender board, reinstall board. SPAN Adjustment 1. 2. 3. 4. 5. 6. 7. 8. Place Analog board on Extender board. Adjust current source to 20mA output. Connect source to input channel under test. Place DMM on A to D input pin for that channel. Power up the board. Adjust 'Span' Pot. until DMM reads 5.00 VDC. Check the 'Zero' adjustment if 'Span' was changed. Turn OFF board, remove Extender board, install board. Dexter Fortson Associates, Inc. Page 20 Analog Output Board P/N 0535 Rev. A USE A CALIBRATED DMM TO SET OUTPUT LEVELS 4-20mA Output Refer to Schematic 045S000535 'Upper Example' for output configuration. OUTPUT Adjustment 1. 2. 3. 4. 5. 6. 7. 8. 9. Place board on Extender Card. Connect DMM (Current Mode) between +12-24vDC and OUTn pin. Connect GNDn to Supply Ground(-). Output a 0hex byte to the Channel Address (n). Adjust pot nO to show 4mA on the DMM. Output a 255hex byte to the Channel Address. Adjust pot nG to show 20mA on the DMM. Output a 128hex byte to the Channel Address. DMM should read between 12.00 and 12.05mA. Voltage Output Refer to Schematic 045S000535 'Lower Example' for output configuration. OUTPUT Adjustment 1. 2. 3. 4. 5. 6. 7. 8. Place Board on Extender Card. Connect DMM (Voltage Mode) between OUTn and ground. Output a 0hex byte to the Channel Address (n). Adjust pot nO to show 0.0v on the DMM (0-5v setting) o-5.00v on the DMM (-5 to +5v setting). Output a 255hex byte to the Channel Address. Adjust pot nG to show +5.00v on the DMM. Output a 128hex byte to the Channel Address. DMM should read 2.50v +/-.02v (0-5v setting) or 0.00v +/-.04v (-5 to +5 setting). Dexter Fortson Associates, Inc. Page 21 Input Examples Use the figures to the Left Counter Input With customer supplied dry contacts, counting inputs are commoned to '+Power' or '+Battery Power' on the Field Wiring board. Use the supplied RTU Worksheet for your site to determine the specific input terminals on the Field Wiring board. Counter inputs must use DFA supplied power as they are Optoisolated on the next board in from the Field Wiring board. (Counter board / Compact I/O board / Expanded I/O board) Analog Input DFA analog inputs are the SINKING type. Within DFA's boards the inputs are commoned to DC ground. Any current device used must be of the SOURCING type, (the device references DC power) The example to the Left is for a two wire device; three wire devices can be connected if they SOURCE current. Optionally a isolated regulated power supply is available should the installation require it. Switch Inputs Customer supplied dry contacts are interconnected to the Relay Input board. The board can be modified for two input voltages; 120 volts AC / DC or 12 volts AC / DC. Revision A boards will have a 1 watt resistor on each input if set for 120 v AC/DC; if set for 12 v AC/DC a jumper wire replaces the resistor. Revision B boards have a removable jumper next to the resistor: the jumper is installed for 12v operation and removed for 120v use. Power in 120v mode comes from the Line board tabs next to the transformer. For 12v mode connect to +P or +BP on the Field Wiring board. Dexter Fortson Associates, Inc. Page 22