Omega OME-A822PG NOTE :, OME-A-822PGL GAIN CONTROL CODE TABLE

2.4.6 A/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

Contents

Main Servicing North America: USA: Canada: For immediate technical or application assistance: USA and Canada: OME-A-822PGH/PGL Page Page 1. Introduction 1.1 General Description 1.2 Features 1.3 Specifications 1.3.1 Power Consumption : 1.3.2 Analog Inputs Caution: refer to Sec. 2.9 first 1.3.3 A/D Converter 1.3.4 DA Converter 1.3.5 Digital I/O 1.3.6 Interrupt Channel 1.3.7 Programmable Timer/Counter 1.3.8 Direct Memory Access Channel (DMA) 1.4 Applications 1.5 Product Check List Attention ! 2. Hardware Configuration 2.1 Board Layout 2.2 I/O Base Address Setting SW1 : BASE ADDRESS 2.3 Jumper Settings 2.3.1 JP1 : D/A Internal Reference Voltage Selection 2.3.2 JP2 : D/A Int/Ext Ref Voltage Selection 2.3.3 JP3 : Single-ended/Differential Selection Refer to Sec. 2.9 first. 2.3.4 JP4 : A/D Trigger Source Selection 2.3.5 JP5 : Interrupt Level Selection 2.3.6 JP6 : User Timer/Counter Clock Input Selection NOTE : if you use A-822_Delay(), the JP6 jumper must be set to internal 2M clock. 2.3.7 JP7 : DMA DACK Selection, JP8 : DMA DRQ Selection 2.4 I/O Register Address 2.4.1 8254 Counter 2.4.2 A/D Input Buffer Register 2.4.3 D/A Output Latch Register NOTE : Send the low 8 bits first, then send the high 4 bits. 2.4.4 D/I Input Buffer Register 2.4.5 Clear Interrupt Request 2.4.6 A/D Gain Control Register NOTE : OME-A-822PGL GAIN CONTROL CODE TABLE OME-A-822PGH GAIN CONTROL CODE TABLE 2.4.7 A/D Multiplex Control Register 2.4.8 A/D Mode Control Register 2.4.9 A/D Software Trigger Control Register 2.4.10 D/O Output Latch Register 2.5 Digital I/O 2.6 8254 Timer/Counter 2.7 A/D Conversion 2.7.1 A/D conversion flow 2.7.2 A/D Conversion Trigger Modes 2.7.3 A/D Transfer Modes 2.7.4 Using software trigger and polling transfer 2.8 D/A Conversion send the low byte data first, then send the high byte data 2.9 Analog Input Signal Connection Page Page Figure 4 Signal Shielding 2.10 Using OME-DB-8225 CJC Output 3. Connector 3.1 CN1/CN2/CN3 Pin Assignment SINGLE-ENDED SIGNAL MODE DIFFERENTIAL SIGNALS 3.2 Daughter Board 3.2.1 OME-DB-8225 3.2.2 OME-DB-37 3.2.3 OME-DB-16P 3.2.4 OME-DB-16R 4. Calibration 4.1 Description of Variable Resistors 4.2 D/A Calibration 4.3 A/D Calibration 5. Diagnostic Utility 5.1 Introduction Page 5.2 Running The Diagnostic Utility 5.2.1 Setup Page 5.2.2 CALIBRATION 5.2.3 FUNCTION TEST Page Page Page Page Page Page Page 5.2.4 SPECIAL TEST Page WARRANTY/DISCLAIMER RETURN REQUESTS/INQUIRIES M4031/0104 Where Do I Find Everything I Need for Process Measurement and Control? OMEGAOf Course! Shop online at www.omega.com TEMPERATURE PRESSURE, STRAIN AND FORCE FLOW/LEVEL pH/CONDUCTIVITY