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OME-DB-889D MULTIPLEXER BOARD .........................................................................................2 1. FUNCTION DESCRIPTION ............................................................................................................2 1.1 FEATURES ........................................................................................................................................2 1.2 APPLICATIONS .........................................................................................
OME-DB-889D Multiplexer Board 1. Function Description The OME-DB-889D is an expansion multiplexer / amplifier board for use with OME-A-82X, OME-PCI-1800 series. Each OME-DB-889D multiplexes 16 differential analog input channels into one analog input of the DAS board. The high grade instrumentation provides software programmable gains of 0.5, 1, 5, 10, 50, 100, 500 and 1000. Thermocouple measurements are handled easily with OME-DB-889D.
z z z z z Gain Common Mode Rejection Non linearity %of FSR Settling Time 0.5 99dB ±0.0004 23uS 1 99dB ±0.0004 23uS 5 114dB ±0.0004 28uS 10 99dB ±0.0004 28uS 50 123dB ±0.0004 140uS 100 123dB ±0.0004 140uS 500 123dB ±0.0008 1300uS 1000 123dB ±0.
2. Installing 2.
2.2 Jumper setup 2.2.1 JP0 ~ JP15 Analog Input R/C Filter The OME-DB-889D provides R/C filter with each analog input channel by jumper setting. 1.2KΩ Channel 0 High 1uF 50V Channel 0 Low 1.2KΩ JP0~JP15 Short : with filter Default setting Open : Without filter 2.2.2 JP16 Analog Output Channel Jumper The OME-DB-889D supports 10 separate jumper to select output channel, This feature permits up to 10 OME-DB-889D’s be connected to a 10 channel analog input card.
2.2.3 JP19 Internal / External Power selection The OME-DB-889D requires single +5V power supply. the connector CN5 are used for the external power supply connection. The OME-A-82X series multi-function card offers +5V power from the 37 pin connector , The OME-DB-889D can be directly from the PC I/O bus by connecting the OME-A-82Xseries multi-function card. JP19 From PC’s +5V Power Default Setting From the CN5 input External +5V power 2.2.
Remote Gain Control When the JP18 is set to “R”, it means Remote Gain Control is selected and the gain is controlled by the digital signal of connector CN3 bit D4, D5, D6. The bit pattern and related gain is illustrated as: CN3 D6 D5 D4 Gain 0 0 0 0.5 0 0 1 1 0 1 0 5 0 1 1 10 1 0 0 50 1 0 1 100 1 1 0 500 1 1 1 1000 Local Gain Control Sw1 1 2 3 4 Gain ON ON ON OFF 0.
2.3 Pin Assignment The OME-DB-889D provides two 37pin D-Sub connector & two 20-pin flat cable connector. The CN1, CN2 D-sub connector is analog output link to analog input connector of OME-A-82X series multi-function card & cascaded another OME-DB-889D. The CN3, CN4 is digital control multiplex & gain setting link to digital output connector of OME-A-82x series multi-function card . CN1 , CN2 Note: AO_n : analog output channel n A.
DOn : DO0~DO3 Multiplexer control bit. DO4~DO6 Gain control bit D.
3 Analog input & Gain setting 3.1 Input Channel Selection The DB-990D provides 15 channel differential analog inputs. Input channel selection is controlled by the 4 bit TTL/CMOS digital data (CN3 DO0~DO3) issued by the OME-A-82x series multi-function card.
3.2 Gain Setting The high grade instrumentation provides software programmable gains or switch selectable gain of 0.5 1, 5, 10, 50, 100, 500, 1000. Software Setting : JP18 should be place on “R” Switch Setting : JP18 should be place on “L” Software Setting (Remote control) Switch Setting (Local Control) Gain DO 6 DO 5 DO 4 SW1-3 SW1-2 SW1-1 0 0 0 ON ON ON 0.
3.3. The Thermocouple Input The OME-DB-889D can accept thermocouple sensor to measure temperature. The OME-DB-889D should be set to different gain value if use different thermocouple type. If you are usingOME-A-82XPGL series multi-function bard to linked OME-DB-889D you have got the gain as: Gain = OME-A-82X Gain X OME-DB-889D Gain OME-A821PGL Gain = 1 , 2 , 4 , 8 50 , 100 , 1000 Examples OME-DB-889D Gain = 0.
3.3.1 Voltage - TO - Temperature Conversion The temperature-versus-voltage relationship of a the thermocouple is not linear. You can reference the thermocouple reference tables to get V to T values. Or use temperature conversion equation to get V to T values. Temperature Conversion Equation: T = a0 + a1 x + a2 x^2 + a3 x^3 + a4 x^4 + ……..
3.3 CJC Output The OME-DB-889D provides Cold-Junction Compensation (CJC) for the thermocouple applications. If the CJC is required, place the JP17 in the position of the channel to be used as a CJC reference. If the CJC is not required, Place the JP17 in the position “X”. CJC has output on connector CN7. Using a voltage meter measures CN7 which exists a voltage related to the OME-DB-889D board temperature. The CJC voltage transfers to temperature with formula: T(°C) = V*1000/24.4 CN7 A.
4 Signal Connection The OME-DB-889D can multiplex up to 16 channel differential inputs. Input channel selection is controlled by a CN3 D4~ D6 digital output by OME-A-82x series multi-function card. 4.1 Floating Signal Connection The OME-DB-889D has only differential input channels, each input channel should be two signal wires. The input should be connected as: CH0HI Floating Signal Source OME-DB-889 D CH0LO Differential signal input OME-DB-889D User’s Manual A.
4.2 Non-Floating Signal Source Some the signal source has one side connect to a local ground. The signal ground with OME-DB-889D ground will not be same voltage level. The input should be show as: CH0HI Common mode Signal Source OME-DB-889D CH0LO A.
4.3 Cascading OME-DB-889D OME-A-82X series A/D card 20 Pin Flat Cable 1. A821PGH/L 2. OME-A-822PGH/L 3. OME-A-823PGH/L OME-DB-889D #2 4. OME-A-826PGH/L 5.
4.4 Open Thermocouple Detection The OME-DB-889D provides open thermocouple detection through a resistor circuitry. These resisters are normally not connected. The user can find on the back of the board has two solder gaps for each input channel. If you short the solder gaps, the open thermocouple detection is enabled. HJ0 100MΩ -15V 1.2KΩ Channel 0 High 1uF 50V Channel 0 Low 1.
4.
5 Programming The OME-A-82x series multi-function card can support up to 160 channels by cascading 10 OME-DB-889D’s without complex programming. 5.1 Using OME-A-822PGL This section will use OME-A-822PGL to link OME-DB-889D. The major steps are listed below: Step 1: Hardware installing. 1. Turn off power of computer. 2. Plug in OME-A-822PGL then connect 37 pin cable & 20 pin flat cables to CN1 and CN3 of OME-DB-889D. 3. Setup OME-DB-889D (Ref. Jumper setting section of OME-DB-889D.
5.3 Example Program DEMO_01.C /* ============== Using OME-A-822 / connect one OME-DB-889D =================*/ #include #include “A822.h” main(void) {int data1,data2; float vol1,vol2; A822_Initialize(0,0x220,-1,-1); /* OME-A-822 Base address in 0x220 ref.
A822_DO(0x0021); /* Send D/O data to OME-DB-889D , Channel 1, Gain=10 */ delay(10); /* delay about 43u sec , Ref. Page 3 Setting time*/ data2=A822_AD_PollingVar(); /* Reading OME-A-822 A/D data */ vol2=(float)((data2-2048)*0.5/2048); printf(“OME-DB-889D channel 1= %6.
6. Calibration The OME-DB-889D is calibrated to its best of operation. For environment subjected to large vibrations, recalibration is recommended. Before calibrating the OME-DB-889D, user should consider having the following available: z z z One 6 digital voltage meter One temperature meter One OME-A-82x series multifunction card 6.1 Calibration VR Description There are two VRs on the OME-DB-889D. VR Num. Description VR1 Amplifier Offset adjustment VR2 CJC Gain adjustment 6.2 Calibration Steps 1.
WARRANTY/DISCLAIMER OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a period of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month grace period to the normal one (1) year product warranty to cover handling and shipping time. This ensures that OMEGA’s customers receive maximum coverage on each product. If the unit malfunctions, it must be returned to the factory for evaluation.
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