Gas Detection System TOX ALARM DG2000-Garage

Transcription

1 Gas Detection System TOX ALARM DG2000-Garage Gas Detection System 32 independent programmable channels 2 programmable alarm levels for each gas = up to 6 for each channel LCD alphanumeric display of gas concentration + precise clock Audible (integrated buzzer) and visual alarm Non-volatile memory for past alarm events 3 SPDT 5A/250 V output relays RS485 (Modbus RTU ), galvanic isolated Sophisticated Sensor I. APPLICATION The Gas Detection System TOX ALARM DG2000-Garage is purposed for detection and control of dangerous concentrations of carbon monoxide (CO), methane (CH4) and propane-butane (LPG) (all 3 or any combination of them). It is applicable in underground garages, tunnels, automobile workshops and engine testing stands, metallurgy & chemical industry factories and other areas, where toxic CO concentrations can be found. To the main control unit TOX ALARM DG2000-Garage can be connected up to 32 sophisticated sensors, mounted in the hazardous areas, which need to be monitored and controlled. The sophisticated sensors are from the series DG510/3G and have a standard range of 0-300ppm CO (up to 1000ppm on request), 0-50% LEL (lower explosion limit) of LPG and CH4. The communication is maintained through serial interface RS485. There are two programmable via the keypad alarm levels for each detected kind of gas pre-alarm AL1 and alarm AL2 connected with 2 integrated SPDT 5A/250V output relays. The two relays are common for all channels. If any detected gas concentration reaches pre-alarm level AL1 and does not decrease under it for a certain period of time (0 999,9 min, adjustable via the keypad), an integrated buzzer starts emitting repeated short beeps, the LED AL1 is lighted up and the output relay AL1 is activated. The relay output may operate a ventilation system in order to clear the air in the dangerous area, any kind of alarm systems, etc. If despite the ventilation the gas concentration exceeds the set alarm level, immediately the buzzer starts emitting a continuous signal, the LED AL2 is lighted up and AL2 output relay is activated, which can operate a stronger ventilation system, a siren, a semaphore system, barriers, alarm lights or other systems to restrict the access of people to the dangerous area until the concentration drops below the alarm level. The Gas Detection System has a non-volatile memory capacity of 30 alarm events. The alphanumeric LCD indicates the 3 different process values of gas concentration of every channel on rotational basis. The user can manually fix the indication to any desired channel. In case of a sensor or cable fault a common for all channels SPDT output relay is activated, LED FLT is lighted up and the audible alarm is activated. DELTA INSTRUMENTS Ltd. 23 A. Saharov blvd., Mladost 1, 1784 Sofia, Bulgaria Tel , , ; Fax: Web Site: delta@deltainst.com

2 II. TECHNICAL SPECIFICATIONS Power supply for control unit 230 V, 50 Hz Power supply for sensors 230 V, 50 Hz Detected Gas Carbon Monoxide (CO), Propane-Butane (LPG), Methane (CH4) Range ppm CO (up to 1000 ppm on request), 0-50% LPG, 0-50% CH4 Pre-alarm level output signal AL1 5A/250V SPDT relay common for all channels Alarm level output signal AL2 5A/250V SPDT relay common for all channels Sensor or cable fault output signal 5A/250V SPDT relay common for all channels Signalization Audible (integrated buzzer) and visual (LEDs) Display LCD, alphanumeric Communication interface with the sensors RS485 Recommended cable type for the RS485 LiYCY 1x2x0.5 (a shielded twisted pair, Ø 0.5 mm 2 ) network between sensors Communication interface to a PC or a RS485 (Modbus RTU), galvanic isolated monitoring & control system Dimensions of control unit 160 x 166 x 102 mm /wall mountable/ Dimensions of a sophisticated sensor 115 x 100 x 40 mm Protection degree of control unit IP65 Protection degree of sensors IP30 Ambient temperature for control unit 0 50 С Ambient temperature for sensors С III. NETWORK SCHEME BMS RS485 (Modbus/RTU) Stations RS485 RS485 RS485 Sensors 2

3 The communication interface between sensors and main control unit is RS485. The following scheme illustrates the topology of such RS485 network. At the one end of the network is placed the main control unit, which has an integrated terminating resistor. Identical terminating resistor should be mounted at the last device of the network as well. The connection cable of each sensor to the main communication cable should not be longer than 2-3 meters. The communication between main control unit and sensors is maintained at the low baud rate of 9600, so it can cover a greater length of up to m. RS485 comp. IV. CONNECTION SCHEME 12V AL 1 AL 2 FLT 220V A B GND A RS485 sen sors B GND +VD _ + L N DESCRIPTION OF TERMINALS Terminal Nr. Description 1,2,3 Galvanic isolated RS485 (Modbus/RTU Slave) for connection with SCADA/HMI. Terminal 1 is +, terminal 2 is -. Terminal 3 is galvanic isolated ground. 4,5 RS485 for communication with sensors. Terminal 4 is +, Terminal 5 is -. 8,9 Back-up power supply accumulator 12VDC. Terminal 8 is +, terminal 9 is - 10,11,12 SPDT relay for pre-alarm level. Terminals 11, 12 are normally open. 13,14,15 SPDT relay for alarm level. Terminals 14, 15 are normally open. 16,17,18 SPDT relay for cable or sensor fault, Terminals 17, 18 are normally open. 19,20,21 Main power supply. Term. 19 phase, Term. 20 zero, Term ground 3

4 Connection of sensors to main control unit CONTROL UNIT A B SENSOR A B SENSOR A B V. MOUNTING INSTRUCTIONS Mount the Gas Detection System on the wall in an area with normal risk of fire. VI. GENERAL CONDITIONS 6.1. TOX ALARM DG2000-Garage may be used only in applications, approved by its manufacturer - DELTA INSTRUMENTS Ltd Test and calibration have to be made every 12 months. The test overall performance will be ensured in a best way through a periodical maintenance servicing contract with the manufacturer The safe operation guarantee is not valid, if the device is maintained with unauthorized personnel or if the corresponding to the term of question Test and Calibration Report is not available If no other parameters are specified, the device is calibrated by the manufacturer with values 50 and 100 ppm CO, 10% and 20% LEL of CH4 and LPG accordingly for pre-alarm and alarm levels and by correct mounting no additional settings should be necessary. VII. OPERATION MODES OF TOX ALARM DG2000-Garage Standard operation mode After switching on the power supply of the main control unit, it enters a standard operation mode of displaying the measured 3 different gas concentration values for each channel on an automatic rotation basis. The upper row of the display indicates Ch CH4 LPG CO and the lower row respectively shows the number of the currently displayed channel, the concentration of methane, propane-butane and carbon monoxide. If any measured value in the lower row blinks, the pre-alarm level AL1 is activated. If the indications of the upper row blink as well, means that the alarm level AL2 is activated too. 4

5 The lower row can display also the following notifications: Offline No response from the sensor Actv The sensor is in activation process (warming up) Fault Sensor s measurement error Not update the control unit has not sent yet a request to the sensor Clock function By pressing the key MODE once while in standard operation mode, the display indicates the real time upper row: hh:mm:ss and lower row date (dd.mm.yy) Manual channel switching mode By pressing the key MODE once again (second time) the display enters a mode for manual switching of all channels. In this mode the operator can go through every channel manually by pressing the and keys. Mode of displaying past alarm events By pressing the key MODE once again (third time) the display enters a mode for visualization of the archive with past alarm events. After entering this mode is displayed the last registered alarm event. The operator can go through all 30 stored past alarms by pressing the and keys. By pressing the key MODE once again (fourth time) the display enters back the standard operation mode. Deactivation of the sound alarm In case of any activated alarm event the sound alarm (buzzer) is triggered as well. It can be deactivated by holding pressed the key ENT. VII. ENTERING PARAMETERS The 32-Channel Gas Detector provides an option for the customer to set for each channel different gas concentration percentage values for the pre-alarm and alarm levels of each type of gas, observing the restrictions 0 AL1 AL2 50 % LEL of CH4 and LPG and 0 AL1 AL2 300ppm for CO. The menu for programming gas detector s parameters is entered from the standard operation mode by pressing and holding the button MODE. It is separated in several submenus, listed in the table below. Traversing the elements of the menu or a submenu is operated by the vertical arrow keys: and. By pressing the button ENT, entering a correct corresponding password and hitting ENT again, the operator can enter a submenu. To exit a submenu, the operator can press MODE. For editing the different parameters of a submenu are used all arrow keys,, and. A newly edited value of any parameter should be saved (confirmed) by pressing the ENT button. 5

6 Indication Submenu s content Password Date Time Submenu for setting the clock (date and time) Alarms Adjusting the pre-alarm and alarm levels of each channel On/Off Ch Activation/ Deactivation of each channel RS-485 Params Modbus RS-485 parameters Others - enabling/disabling the audible alarm setting the reaction delay of AL1 output relay Factory Sett. Parameters, accessible only by manufacturer The accessible for adjusting parameters are listed in the following table: Date Time - Submenu for setting the clock of the control unit Date E Date setting in the form: dd.mm.yyyy Time E Time setting in the form: hh:mm:sec Alarms - Adjusting the pre-alarm and alarm levels of each channel LL CH4 Pre-alarm level of methane in % LL LPG Pre-alarm level of propane-butane in % LL CO Pre-alarm level of carbon monoxide (CO) in ppm HL CH4 Alarm level of methane in % HL LPG Alarm level of propane-butane in % HL CO Alarm level of carbon monoxide (СО) in ppm On/Off Channels Activation / Deactivation of each channel Channel 1 Activation / Deactivation of channel 1 Channel 2 Activation / Deactivation of channel Channel 32 Activation / Deactivation of channel 32 RS-485 Params - Modbus RS-485 Parameters Device Addr Address of the device Baud rate Baud Rate Others On/Off Siren Enabling / Disabling the Audible Alarm AL1 Delay sec Reaction Delay of the Pre-alarm Output Relay in seconds 6

7 APPENDIX А DESCRIPTION OF MODBUS COMMUNICATION PROTOCOL 1. The device conforms to a subset of the MODBUS over Serial Line (RS 485) specification V 1.0. Only RTU transmission mode of characters is supported. For detailed information about the Modbus protocol visit 2. The device utilizes the following configuration: Baudrate = "1200","2400","4800","9600","14400" Databits = 8 Parity = none Stopbit = 1 3. Connection scheme: It is required to place Line termination resistors (LT) near each of the ends of the bus with typical value of 360 Ohms (0.5W resistor). There is an integrated LT resistor in the main gas detection unit DG2000, so there needs to be placed only 1 more at the other end of the bus. 7

8 4. Input Registers (Read Only): Address Description Two 16-bit registers, indicating if the corresponding channel is activated or deactivated. The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) = activated channel. Two 16-bit registers, indicating if there is received data from the sensor. When DG2000 is turned on, it starts reading measured data from each sensor. Set bit (=1) means that the sensor has been initially read. The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Two 16-bit registers, indicating if a sensor is Offline (does not respond). The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) means that the sensor is offline. Two 16-bit registers, indicating if there is an error by the measurement of methane (e.g. disconnected sensor). The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) means that there is an error. Two 16-bit registers, indicating if there is an error by the measurement of propane-butane (e.g. disconnected sensor). The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) means that there is an error. Two 16-bit registers, indicating if there is an error by the measurement of carbon monoxide (CO) (e.g. disconnected sensor). The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) means that there is an error. Right after connecting DG2000 to the power supply, the sensors undergo an activation (warming up) process for about 30 sec. The values, measured by sensors during their activation process should not be considered real. So if a sensor is warming up, the corresponding bit will be set (=1). The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. These 16-bit registers indicate if a channel s pre-alarm level is activated. The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) = activated pre-alarm level. These 16-bit registers indicate if a channel s alarm level is activated. The least significant bits of both registers correspond respectively to channels 1 and 17. The most significant bits channels 16 and 32. Set bit (=1) = activated alarm level. Pre-alarm level for СН4 Alarm level for СН4 Pre-alarm level for LPG Alarm level for LPG Pre-alarm level for СO Alarm level for СO 8