Table B-4. Differential Voltage Ranges | Digi RCM4000 specification

Many other possible ranges are possible by physically changing the resistor values that make up the attenuator circuit.

NOTE: Analog input LN7_IN does not have the 10 kΩ resistor installed, and so no resistor attenuator is available, limiting its maximum input voltage to 2 V. This input is intended to be used for a thermistor that you may install at header location JP25.

It is also possible to read a negative voltage on LN0_IN–LN5_IN by moving the 0 Ω jumper (see Figure B-6) on header JP23 or JP24 associated with the A/D converter input from analog ground to the reference voltage generated and buffered by the A/D converter. Adjacent input channels are paired; moving the jumper on JP 23 changes both of the paired channels (LN4_IN–LN5_IN), and moving the jumper on JP24 changes LN0_IN– LN3_IN. At the present time Rabbit Semiconductor does not offer the software drivers to work with single-ended negative voltages, but the differential mode described below may be used to measure negative voltages.

Differential measurements require two channels. As the name differential implies, the dif- ference in voltage between the two adjacent channels is measured rather than the differ- ence between the input and analog ground. Voltage measurements taken in differential mode have a resolution of 12 bits, with the 12th bit indicating whether the difference is positive or negative.

The A/D converter chip can only accept positive voltages, as explained in Section 4.4. Both differential inputs must be referenced to analog ground, and both inputs must be positive with respect to analog ground. Table B-4provides the differential voltage ranges for this setup.

Table B-4. Differential Voltage Ranges

Min. Differential

Voltage

(V)

Max. Differential

Voltage (with

prescaler)

(V)

A/D Converter

Gain

mV per Tick

0	±22.528	1	11

0	±11.264	2	5.5

0	±5.632	4	2.75

0	±4.506	5	2.20

0	±2.816	8	1.375

0	±2.253	10	1.100

0	±1.408	16	0.688

0	±1.126	20	0.550

User’s Manual

101

Image 107

Digi RCM4000 user manual Table B-4. Differential Voltage Ranges

Contents

RabbitCore RCM4000 Rabbit Semiconductor Trademarks Table of Contents Software Reference Appendix C. Power Supply 109 RabbitCore RCM4100 Introduction Feature RCM4000 RCM4010 RCM4000 FeaturesRCM4000 Features Advantages of the RCM4000 1 RCM4000 Development Kit Development and Evaluation Tools Online Documentation Software RabbitCore RCM4000 Getting Started Install Dynamic C Prepare the Prototyping Board for Development Hardware Connections Prototyping Board Attach Module to Prototyping Board Connect Programming Cable AC Adapter Connect Power Run a Sample Program TroubleshootingRun a Sample Program Technical Support Where Do I Go From Here? RabbitCore RCM4000 Introduction Running Sample Programs Sample Programs User’s Manual Use of Nand Flash RCM4000 only Click OK or Close to exit the various dialog boxes Serial Communication User’s Manual Real-Time Clock 3 A/D Converter Inputs RCM4000 only RabbitCore Module Hardware Reference Shows the RCM4000 pinouts for header J3 RCM4000 Digital Inputs and Outputs 4000 Pin Pin Name Default Use Alternate Use RCM4000 Pinout Configurations TXD PC0 PE1 Other Inputs and Outputs Memory I/O Interface Serial Ports Rabbit 4000 Serial Port and Clock PinsSerial Communication RJ-45 Ethernet Port Pinout Ethernet Port Programming Port Programming Cable Changing Between Program Mode and Run Mode Standalone Operation of the RCM4000 Resistor Divider Network for Analog Inputs A/D Converter RCM4000 only It is not referenced to Analog Supply Circuit 1 A/D Converter Power Supply Spectrum Spreader Other HardwareClock Doubler Nand Flash MemorySram Flash Eprom RabbitCore RCM4000 More About Dynamic C Software Reference RabbitCore RCM4000 Sram Use Dynamic C Function CallsDigital I/O Serial Communication Drivers RabbitCore RCM4000 Board Initialization Prototyping Board Functions Alerts Void timedAlertunsigned long timeout Analog Inputs RCM4000 only ADS7870 Signal ADS7870 State RCM3400 Function/State On write operations Data value on read operations Gain Code Multiplier Unsigned int anaInDriverunsigned int cmd, unsigned int len AnaInConfig, anaIn, brdInit Gain Code Multiplier Voltage Range Single Diff ×10 ×16 ×20 126 Applies to Prototyping Board If successful If not able to make calibration constants Channel Code Single-Ended Voltage Range † Input Lines Float anaInVoltsunsigned int channel, unsigned int gaincode Float anaInDiffunsigned int channel, unsigned int gaincode Channel Code 20 mA Input Lines Float anaInmAmpsunsigned int channel Allchan Gain Code Voltage Range +AIN7 AIN6 Gain Code Voltage Range Add-On Modules Upgrading Dynamic C RabbitCore RCM4000 TCP/IP Connections Using the TCP/IP Features RabbitCore RCM4000 TCP/IP Primer on IP Addresses Typical Corporate Network IP Addresses Explained How IP Addresses are Used Dynamically Assigned Internet Addresses Placing Your Device on the Network Direct Connection Direct Connection Using a HubRunning TCP/IP Sample Programs How to Set IP Addresses in the Sample Programs Direct Connection PC to RCM4000 Module How to Set Up your Computer for Direct Connect Running Additional Sample Programs With Direct Connect Run the PINGME.C Sample Program Where Do I Go From Here? RabbitCore RCM4000 Appendix A. RCM4000 Specifications Dia × Electrical and Mechanical Characteristics Exclusion Zone Parameter RCM4000 RCM4010 Table A-1. RCM4000 Specifications Ten 8-bit timers 6 cascadable from the first Parameter Test Conditions Table A-2 Converter Specifications1 A/D Converter Figure A-3. User Board Footprint for RCM4000 Headers Symbol Parameter Min Typ Max Rabbit 4000 DC CharacteristicsTable A-4 .3 Volt DC Characteristics Symbol Parameter Maximum Rating Table A-6. External Capacitive Bus Loading -40C to +85C I/O Buffer Sourcing and Sinking LimitBus Loading Table A-5. Capacitance of Rabbit 4000 I/O Ports Iord Clock to Address Worst-Case Table A-8. Preliminary Data and Clock DelaysOutput Delay 30 pF 60 pF 90 pF Ns setting No dbl / dbl Conformally coated Area Conformal Coating Header Description Pins Connected Factory Default Jumper ConfigurationsTable A-9. RCM4000 Jumper Configurations RabbitCore RCM4000 Appendix B. Prototyping Board Current Measurement Headers RCM4000 Prototyping Board Features RabbitCore RCM4000 935 Mechanical Dimensions and Layout Parameter Specification Power SupplyTable B-1. Prototyping Board Specifications Signals Using the Prototyping Board Pin Pin Name Prototyping Board Use Measuring Current Draw Adding Other Components 3.1 A/D Converter Inputs Analog Features RCM4000 onlyTable B-3. Positive A/D Converter Input Voltage Ranges Table B-4. Differential Voltage Ranges 3.3 A/D Converter Calibration Mode Read CalibrateThermistor Input Serial Port Header Default Use Alternate Use Table B-5. Prototyping Board Serial Port Configurations 4.1 RS-232 Table B-6. RCM3400 Prototyping Board Jumper Configurations Prototyping Board Jumper Configurations JP5 LN4IN-LN6IN 108 Battery-Backup Circuits Appendix C. Power SupplyPower Supplies 165 mA·h = 2.5 years Reset Generator User’s Manual 111 112 SMODE0 SMODE1 Index ADCALALL.C User’s Manual 115 116 Schematics