Model 840 Gas Detection/Alarm System Operator’s Installation and Instruction Manual DETCON, Inc. 3200 Research Forest Dr., The Woodlands, Texas 77387 Ph.281.367.4100 / Fax 281.298.2868 www.detcon.com November 1, 2010 • Document #2925 • Revision 1.
840 Operators Manual This page left intentionally blank Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381 Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067 Phone: 888.367.4286, 281.367.4100 • Fax: 281.292.2860 • www.detcon.com • sales@detcon.com Model 840 Operator Manual Rev. 1.
840 Operators Manual Table of Contents 1. 2. 3. 4. Description..............................................................................................................................................1 System Operation...................................................................................................................................2 Specifications..........................................................................................................................................
840 Operators Manual 10. Spare Parts .......................................................................................................................................28 11. Warranty ..........................................................................................................................................28 Appendix A...................................................................................................................................................29 Revision Log..........
840 Operators Manual 1. Description Housed in a NEMA 4X weatherproof enclosure, the Detcon Model 840-N4X Gas Detection Alarm System has the capability to handle eight 4-20mA sensor inputs or eight RS485 serial sensor inputs. The remotely mounted gas sensor, (purchased separately), can include any Detcon 4-20mA or RS-485 serial input device such as combustible gas, toxic gas, or oxygen deficiency sensors. The system displays real time channel information on a backlit LCD.
840 Operators Manual 2. System Operation The Model 840-N4X can be configured for either eight 4-20mA sensor inputs or eight RS-485 serial sensor inputs via a dipswitch selection. The system displays current status information on its LCD display. The information displayed during normal operation includes the gas channel #, current reading and gas type.
840 Operators Manual Specifications 3. Capacity Sensor Inputs Electrical Accuracy Analog 4-20mA or RS-485 Modbus RTU ± 1% Full Scale Range Qty 4 Relays: 2 Form C Contacts per relay Rated for 5A @ 30VDC, 5A @ 250VAC Outputs Power Input Power Consumption Physical 8 Input Channels RS-485 (Standard) RS-232 for Uploading/Downloading to PC (Standard) 115-230VAC 11.
40 Operators Manual 4. Installation 4.1 Mounting and Cable Penetrations Securely mount the Model 840 N4X enclosure per the mounting dimensions provided in Figure 2. Provide for suitable conduit/cable entries in the bottom of the enclosure. Keep AC power separate from DC signals in conduit connections and runs. Mounting Holes 5/16 Dia. Figure 2 Dimensional View of Enclosure 4.
840 Operators Manual 4.2.2 DC Power For optional DC power input, connect 11.5-30VDC to the terminals at J8, labeled “DC IN” in Figure 3 and Figure 4. This input can be used for primary power or back-up power in the event of a VAC power failure.
840 Operators Manual PS1 SW2 SW3 + PS2 VOLTAGE SELECT BATTERY SW1 VAC POWER SWITCH SW4 SW0V EXTERNAL AC IN J2 J8 Battery Restore Switch EXTERNAL DC IN VDC POWER SWITCH JP1 Jumper for RS-485 Shield to Earth Grnd. Figure 4 Mother Board Layout Model 840 Operator Manual Rev. 1.
840 Operators Manual Ribbon Cable to LCD SW1 - Options 4 - Password Protection 3 - Not Used 2 - 600/700 Series Sensors or Mod 10 Controllers. 1 - Analog or Serial Mode RS-485 Input for Gas Sensor ON OFF 1 2 3 4 Ni-Cad Battery Ribbon Cable to Mother Board AUX AUX Figure 5 Control Board Layout 4.2.4 Serial Input Gas Sensors When connecting serial input gas sensors such as the Detcon 600 Series, terminate the 3 conductors from the serial cable in the following manner.
840 Operators Manual 4.2.5 Serial Polling of the Model 840 Controller When polling this device serially, connect the incoming RS-485 wiring to the terminals labeled “RS-485 IN” (J10) on the Motherboard. For connection to the next polled device in the serial loop, connect the RS485 wiring to J31 labeled “RS-485 OUT”. These terminals are labeled “A”, “B”, and “S” (Shield) for standard RS-485 Modbus™ communication as shown in Figure 4.
840 Operators Manual 5. Start-up NOTE: Before applying power, check and make sure that all the wiring connections and external devices are installed correctly. NOTE: Applying power with devices hooked up incorrectly may cause damage to the equipment. 5.1 Power Switch Selections Refer to Figure 6. For AC power, locate the V-SELECT switch (SW2) and select the appropriate voltage setting.
840 Operators Manual 6. System Configuration 6.1 Analog/Serial input selection On the Controller PCB, switch SW1 position 1 is used to select between Analog or Serial sensor inputs for the 840 Controller. Switch SW1-1 must be placed in the “ON” position for the unit to accept Serial RS-485 Modbus™ sensors, and SW1-1 must be placed in the “OFF” position if the sensors are 4-20mA type sensors (Figure 7).
840 Operators Manual 6.3.1 PROG Key: From the Main Display, the PROG key enters into the Main Menu. Once inside the Main Menu, the PROG key acts as an “Escape” key that moves backwards in the Menu flow chart. NOTE: While in Menu Mode there are no updates to gas readings and hence no alarms will take place. 6.3.2 “Up Arrow” Key: This key moves the user up the Main Menu flow chart. It is also used to change highlighted entries within menu selections in the upward direction. 6.3.
840 Operators Manual NOTE: The controller automatically times out of Menu Mode and returns to the Main Display after 1 minute of inactivity. 6.4 Main Display Functions The Main Display is a 1¼”x 6” backlit LCD that has 4 lines by 40 characters. In normal operation “CH # = XX ppm GAS” will be displayed. If any channel is in any gas alarm condition, the “CH#” will change to “ALM”. If any gas channels are in Fault, they will display “CH # = IN FAULT”.
840 Operators Manual 6.5.1 Menu Flow Chart NORMAL OPERATION MAIN DISPLAY MAIN MENU CALIBRATION MODE CALIBRATION MODE ON/OFF MAIN MENU SET # OF CHANNELS SET # OF CHANNELS #### MAIN MENU SET CHANNEL RANGE SET CHANNEL RANGE CHX = XXXXX CH1 ... CHX MAIN MENU SET CHANNEL TYPE SET CHANNEL TYPE CHX = #### CH1 ...
840 Operators Manual 6.5.2 Calibration Mode This menu entry allows CALIBRATION MODE to be toggled “ON” or “OFF”. With CALIBRATION MODE on, the attached sensor can be calibrated without triggering any alarms. While the controller is in CALIBRATION MODE, the Main Display will show each channel as “CH # = IN CAL”. The controller will automatically time out of CAL MODE after 60 minutes. The menu appears as: CALIBRATION MODE: ON or OFF NOTE: Some Detcon sensor models (Series 500/600/700) give a 2.
840 Operators Manual 6.5.6 Set Channel Alarms This menu entry allows the selection of the Channel Alarms for each gas channel input. These represent the alarm level set points. These set points can be entered in 5% increments of the full-scale range selected for that channel. Selection of ascending (right arrow) or descending (left arrow) alarms is also made in this menu selection. This menu appears as: SET CHANNEL ALARMS: CH1 – ALM1 = X.
840 Operators Manual 6.5.9 Set Modbus Address: This menu entry allows for the setting of the serial address of this controller when it is to be polled by another master device via RS485 Modbus RTU. This should be set in hexadecimal format. SET MODBUS ADDRESS: 01 6.5.10 View TWA and Peak Readings This menu entry is used to view the recorded TWA and Peak readings for the different gas channels.
840 Operators Manual 6.6 Alarm Test Mode Alarm conditions can be simulated and relay contacts can be verified by use of this special software feature. To activate the Alarm Test Mode, hold the z (Down) key for 5 seconds while in the Main Display Mode. After holding the z (Down) key for 5 seconds there will be an audible “Chirp”, then all active gas channels will display “CH# 00 TESTING”. The readings will increment up at 1% full scale per second.
840 Operators Manual 7. System Features 7.1 Modbus Communications The model 840 controllers feature a Modbus compatible communications protocol and are addressable by a PLC, PC/HMI, DCS, or other Modbus RTU master-polling devices. Communication is accomplished by two wire half duplex RS-485, 9600 baud, 8 data bits, 1 stop bit, no parity, through the controllers secondary port. Wiring should be brought directly to J10 located on the motherboard.
840 Operators Manual Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Low Byte Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Not Used Not Used Not Used Not Used Not Used 1 = Channel 8 Alarm 1 1 = Channel 7 Alarm 1 1 = Channel 6 Alarm 1 1 = Channel 5 Alarm 1 1 = Channel 4 Alarm 1 1 = Channel 3 Alarm 1 1 = Channel 2 Alarm 1 1 = Channel 1 Alarm 1 0 = Channel 8 no Alarm 1 0 = Channel 7 no Alarm 1 0 = Channel 6 no Alarm 1 0 = Channel 5 no Alarm 1 0 = Channel 4 no Alarm 1 0 = Channel 3 no Alarm 1 0 = Channel 2 no Alarm 1 0 = C
840 Operators Manual 40012 Cal Status Bits High Byte Bit 7 Not Used Bit 6 Not Used Bit 5 Not Used Bit 4 Not Used Bit 3 Not Used Bit 2 Not Used Bit 1 Not Used Bit 0 Not Used Low Byte Bit 7 1 = Channel 8 Cal Bit 6 1 = Channel 7 Cal Bit 5 1 = Channel 6 Cal Bit 4 1 = Channel 5 Cal Bit 3 1 = Channel 4 Cal Bit 2 1 = Channel 3 Cal Bit 1 1 = Channel 2 Cal Bit 0 1 = Channel 1 Cal 0 = Channel 8 no Cal 0 = Channel 7 no Cal 0 = Channel 6 no Cal 0 = Channel 5 no Cal 0 = Channel 4 no Cal 0 = Channel 3 no Cal 0 = Channe
840 Operators Manual Figure 10 Serial connection and jumper locations Make the connection from the Model X40 controller to your PC (COM1) using the supplied cable. The controller’s 1/8” jack connection is located on the bottom of the PCB. From the Start menu, select Programs> Accessories> Communications> Hyper Terminal. Figure 11 Invoking Hyper Terminal Hyper Terminal will open with the following Connection Description Dialog box. Type “X40 Download” as the name for the connection and click ‘OK’.
840 Operators Manual Figure 12 Connection Description The “Connect To” Dialog box will appear. For Connect using: choose COM1 and Click OK. Figure 13 Connect to Configuration The COM1 Properties Dialog box will appear. Insure the settings are: Bits per second: 9600 Data bits: 8 Parity: None Stop bits: 1 Flow control: None Click OK. Model 840 Operator Manual Rev. 1.
840 Operators Manual Figure 14 Communications port properties From the main menu Select: Transfer> Capture Text. Figure 15 Setting up capture Select a Name and location where the downloaded data is to be saved, and click “Start”. The file will be saved as a text file and the file extension of *.txt should be used. Model 840 Operator Manual Rev. 1.
840 Operators Manual Figure 16 Naming Capture File On the X40 controller, enter the main menu. Scroll down to “MAIN MENU:” “DOWNLOAD HISTORY”. Press the Enter button. The display should read “STREAMING DATA…..” Once the controller has finished sending data to the PC, it will return to the main menu. If no buttons are pressed, the controller will return to normal operation. If the download was successful the display should look similar to figure 7 on the PC.
840 Operators Manual Figure 18 Saving file Disconnect the controller from the PC. The raw data from the controller is now stored in the file and location selected, and available for the user to use as desired. Model 840 Operator Manual Rev. 1.
840 Operators Manual 8. Options 8.1 Option for Battery Back-up Operation This option provides a nominal 1-hour of battery back-up power to the Gas Detection Alarm System. The battery back-up system consists of two 12VDC / 0.8 Amp-hour batteries in series, along with the requisite low voltage cut-off circuitry. The batteries may be isolated during exchange or while in long-term storage by using the battery disconnect switch shown in Figure 4.
840 Operators Manual 8.4 Optional Type Z Enclosure Purge Assembly Model X40 controllers are available with an optional, externally mounted, Model 1001A Z-Purge system. This purge assembly achieves a Class 1, Division 2, Group CD area classification. The Type Z-Purge assembly is installed on the X40 Controller at the Detcon factory. The Z-Purge option is factory wired to automatically removed AC power from the controller if there is a loss of pressure.
840 Operators Manual 9. Troubleshooting Guide Problem Unit will not Power Up Potential Fix erroneous information seconds during power-up recycle (Screen will display “Restoring Defaults) → Re-enter all Channel and alarm information. → Insure that no channels are set to ascending or descending incorrectly. → Check that Alarm Annunciators current draw does not exceed the on-board Power Supply limitations. Replace with external Power Supply if necessary. → SW1-1 must be set to “OFF” position.
840 Operators Manual Appendix A Revision Log Revision 1.8 Date 01/12/2009 1.9 11/1/2010 Changes made Approval Correction to Password Protection switch direction BM Section 6.2 Correction to Note regarding use of Calibration Mode LU when sensors in calibration, Section 6.5.2 Shipping Address: 3200 A-1 Research Forest Dr., The Woodlands Texas 77381 Mailing Address: P.O. Box 8067, The Woodlands Texas 77387-8067 Phone: 888.367.4286, 281.367.4100 • Fax: 281.292.2860 • www.detcon.com • sales@detcon.
