Omega OME-A822PG manual 6 A/D Gain Control Register, GAIN3 GAIN2 GAIN1 GAIN0

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2.4.6A/D Gain Control Register

(WRITE)	Base+9 : A/D Gain Control Register Format
Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
X	X	X	X	GAIN3	GAIN2	GAIN1	GAIN0

The only difference between the OME-A-822PGL and OME-A-822PGH is the GAIN control function. The OME-A-822PGL provides gains of 1/2/4/8 and the OME-A-822PGH provides gains of 1/10/100/1000. The gain control register control the gain of the A/D input signal. Bipolar/Unipolar will affect the gain factor.

It is important to select the correct gain-control-code according to Bipolar/Unipolar input.

NOTE : If the gain control code is changed, the hardware needs an extra delay for

the gain settling time. The gain settling time is different for the different gain control codes.

The software driver does not take care the gain settling time, so the user needs to add

the delay . If the application program will run on different machines, the user needs to implement a machine independent timer. The software driver, A-822_delay(),is designed for this purpose. If this subroutine is used, then counter2 as described in sec 2.6 is reserved by the software driver to implement the machine independent timer.

OME-A-822PGL GAIN CONTROL CODE TABLE

BI/UNI	Settling Time	GAIN	Input Range	GAIN3	GAIN2	GAIN1	GAIN0
BI	23 us	1	+/- 5V	0	0	0	0
BI	23 us	2	+/- 2.5V	0	0	0	1
BI	25 us	4	+/- 1.25V	0	0	1	0
BI	28 us	8	+/- 0.0625V	0	0	1	1
UNI	23 us	1	0V to 10V	0	1	0	0
UNI	23 us	2	0V to 5V	0	1	0	1
UNI	25 us	4	0V to 2.5V	0	1	1	0
UNI	28 us	8	0V to 1.25V	0	1	1	1
BI	23 us	0.5	+/- 10V	1	0	0	0

BI=Bipolar, UNI=Unipolar, X=don‘t care, N/A=not available

OME-A-822PGL/PGH Hardware Manual ---- 20

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Contents User’sGuide Benelux CanadaMexico Czech RepublicOME-A-822PGH/PGL Tables of Contents IntroductionConnector Features General DescriptionAnalog Inputs SpecificationsPower Consumption 3 A/D ConverterDigital I/O DA ConverterInterrupt Channel Programmable Timer/Counter Direct Memory Access Channel DMAApplications Product Check ListHardware Configuration Board LayoutI/O Base Address Setting Default base address isJumper Settings 1 JP1 D/A Internal Reference Voltage Selection2 JP2 D/A Int/Ext Ref Voltage Selection 3 JP3 Single-ended/Differential Selection4 JP4 A/D Trigger Source Selection 5 JP5 Interrupt Level Selection6 JP6 User Timer/Counter Clock Input Selection 7 JP7 DMA Dack Selection JP8 DMA DRQ Selection DRQ JP7 Dack JP8 DMAI/O Register Address Address Read Write2 A/D Input Buffer Register 1 8254 CounterConversion is completed, the Ready bit will clear to zero 3 D/A Output Latch Register 4 D/I Input Buffer Register Clear Interrupt Request6 A/D Gain Control Register GAIN3 GAIN2 GAIN1 GAIN0OME-A-822PGH Gain Control Code Table 7 A/D Multiplex Control Register8 A/D Mode Control Register 9 A/D Software Trigger Control Register 10 D/O Output Latch Register Digital I/O CN28254 Timer/Counter CounterA/D Conversion 1 A/D conversion flow Polling, interrupt and DMA2 A/D Conversion Trigger Modes 3 A/D Transfer ModesDelay the settling time refer to Sec .4.6 and Sec Using software trigger and polling transferRefer to Sec D/A Conversion Analog Input Signal Connection OME-A-822PGL/PGH Hardware Manual OME-A-822PGL/PGH Hardware Manual Signal Shielding Use a single connection to frame ground not A.GND or D.GNDUsing OME-DB-8225 CJC Output CN1 Digital Input Pin Assignment CN1/CN2/CN3 Pin AssignmentCN2 Digital Output Pin Assignment SINGLE-ENDED Signal Mode Differential Signals OME-DB-37 Daughter BoardOME-DB-8225 OME-DB-16PCalibration Description of Variable ResistorsD/A Calibration A/D Calibration Diagnostic Utility IntroductionOME-A-822PGL/PGH Hardware Manual Running The Diagnostic Utility Setup Base address selection screenDMA no and IRQ no selection screen Calibration Function Test Test Test Screen Digital I/O Test Screen Multiplexer Test Screen Use IRQ Test Screen Use DMA Test Screen DA Gain Test Screen Timer 0 Test Screen Special Test Help WARRANTY/DISCLAIMER Temperature