#include <rb8509_adc12.h>
Inherits RulbusDevice.
Measure a voltage.
Module RB8509 is a 8-channel 12-bit analog to digital converter (ADC).
The module has eight analog inputs and a trigger input to start a data acquisition. A data acquisition can also be started by a software trigger.
Module RB8509 contains the following parts:
At production time, the ADC is configured for unipolar or bipolar operation and its input voltage range is defined as 10 or 20V.
The module cannot be queried about these settings, so they must be specified when the ADC is created through its constructor. When a ADC is created, it is configured with the following defaults:
.*) via constructor default argument
The following table shows the volt-per-bit values for the various input voltage ranges.
Voltage range | volt-per-bit bipolar
----------------------+--------------------------
0 .. 10.2375 V | 2.5 mV 0
-5.12 .. 5.1175 V | 2.5 mV 1
-10.24 .. 10.235 V | 5 mV 1
The class provides methods to select the input-channel and gain and to obtain these settings and it provides methods to read the input as (raw) ADC-value or as voltage at the channel's input.
Rulbus::RB8510_Adc12 adc( "adc" ); adc.setChannel( 3 ); adc.autoscale(); std::cout << adc.name() << ": channel " << adc.channel() << ", gain " << adc.gain() << ": " << adc.voltage() << std::endl;
Module RB8509 contains an input multiplexer, a programmable amplifier and a 12-bit ADC. The table below shows how these parts can be controlled and how information can be obtained from them.
Register Offset Rd/Wr Description
----------------------------------------------------------------------------
adclsb 0 read ADC least significant byte;
resets the end of conversion flip-flop.
control 0 write control register
76543210
7 : interrupt enable (active high)
6 : ext. trigger enable (active high)
54 : gain number selector (1,2,4,8)
3 : multiplexer enable (active low)
210 : channel selector
status 1 read data and status register
76543210
7 : external trigger
6 : interrupt pending
5 : end of conversion (EOC)
4 : ADC busy flag
3210 : high order nibble
convert 1 write (start conversion)
76543210 : don't care
Public Types | |
| typedef Int | Value |
| ADC conversion data type. | |
Public Member Functions | |
Construction | |
| RB8509_Adc12 (NameCref aName, Addr aAddr=DEF_ADDR, Rack aRack=DEF_RACK, bool aBipolarFlag=DEF_BIP, Real aVoltPerBit=DEF_VPB, bool aExtTrigInpFlag=DEF_ETI) | |
| constructor. | |
| ~RB8509_Adc12 () | |
| destructor. | |
Accessors | |
| int | channel () const |
| the current channel number [0..7]. | |
| int | gain () const |
| the current gain [1,2,4,8]. | |
| Volt | voltage () |
| issue software trigger and return input-voltage measured; may throw RulbusTimeoutError; or wait for external trigger and return input-voltage measured. | |
| Value | value () |
| issue software trigger and return conversion value; may throw RulbusTimeoutError; or wait for external trigger and return conversion value. | |
| Value | result () |
| return last (bipolar) conversion result; requires preceding external trigger or software trigger; when using the latter, it may throw RulbusTimeoutError. | |
| Value | rawresult () |
| return last raw conversion result; requires preceding external trigger or software trigger; when using latter, it may throw RulbusTimeoutError. | |
| bool | hasExtTriggerInput () const |
| true if ADC has trigger input available. | |
| bool | extTriggerLevel () const |
| the current external trigger level; requesting the level for a non-available trigger input throws a RulbusContextError. | |
| bool | isEnabledExtTrigger () const |
| true if external trigger-input is enabled. | |
| bool | isEnabledMultiplexer () const |
| true if multiplexer is enabled. | |
| bool | isEnabledInterrupt () const |
| true if interrupt is enabled. | |
| bool | isBusyAdc () const |
| true while ADC is converting. | |
| bool | isReady () const |
| true if result is available; flag is reset by reading result. | |
| bool | isBipolar () const |
| true if ADC has bipolar configuration. | |
| bool | isPendingInterrupt () const |
| true if an interrupt is pending; flag is reset by reading result. | |
| Real | voltperbit () const |
| the ADC's input sensitivity configuration. | |
Predicates | |
| bool | isValidChannel (int aChannel) const |
| true if channel is valid. | |
| bool | isValidGain (int aGain) const |
| true if gain is valid. | |
Mutators | |
| void | setChannel (int aChannel) |
| select a new channel [0..7]; may throw RulbusRangeError. | |
| void | setGain (int aGain) |
| select new amplifier gain [1,2,4,8]; may throw RulbusRangeError. | |
| void | autoscale () |
| determine amplifier gain to fit current signal. | |
| void | convert () |
| start an analog to digital conversion. | |
| bool | enableMultiplexer (bool enable=true) |
| enable or disable multiplexer. | |
| bool | enableExtTrigger (bool enable=true) |
| enable or disable external trigger-input; enabling a non-available trigger input throws a RulbusContextError. | |
| bool | enableInterrupt (bool enable=true) |
| enable or disable interrupt. | |
Static Public Attributes | |
Defaults | |
| const Addr | DEF_ADDR = 0xC0 |
| default address | |
| const int | DEF_GAIN = 1 |
| default gain value | |
| const int | DEF_CHAN = 0 |
| default channel number | |
| const bool | DEF_BIP = true |
| default bipolar | |
| const Real | DEF_VPB = 5e-3 |
| default bipolar, -10.24..+10.23V | |
| const bool | DEF_ETI = false |
| default no external trigger input | |
Limits | |
| const int | LIM_MINCHAN = 0 |
| min. value for channel selection | |
| const int | LIM_MAXCHAN = 7 |
| max. value for channel selection | |
| const int | LIM_MINGAIN = 1 |
| min. value for gain selection | |
| const int | LIM_MAXGAIN = 8 |
| max. value for gain selection | |
| const Real | LIM_MINVPB |
| min. value for volt per bit | |
| const Real | LIM_MAXVPB |
| max. value for volt per bit | |
| const int | LIM_TIMOUT = 1000 |
| maximum conversion-ready testloops | |
| const Value | LIM_MINVAL = 0x0000 |
| min. value for unipolar ADC-code | |
| const Value | LIM_MAXVAL = 0x0FFF |
| max. value for unipolar ADC-code | |
| const Value | LIM_BIPVAL = 0x0800 |
| offset value for bipolar ADC-code | |
Protected Member Functions | |
Construction and Assignment | |
| RB8509_Adc12 () | |
| prevent default construction | |
| RB8509_Adc12 (RB8509_Adc12Cref rhs) | |
| prevent copying | |
| RB8509_Adc12Ref | operator= (RB8509_Adc12Cref rhs) |
| prevent copying | |
Checkers | |
| void | checkChannel (int aChannel) const |
| check if channel is valid; may throw RulbusRangeError. | |
| void | checkGain (int aGain) const |
| check if channel is valid; may throw RulbusRangeError. | |
Private Attributes | |
Data | |
| Byte | theControlRegister |
| control-register contents | |
| bool | theExtTrigInpFlag |
| ADC has external trigger input. | |
| bool | theBipolarFlag |
| ADC is bipolar. | |
| Real | theVoltPerBit |
| ADC input sensitivity. | |
Static Private Attributes | |
Register offsets | |
| const int | OFF_ADCLSB = 0 |
| data low order byte | |
| const int | OFF_CONTROL = 0 |
| control-register | |
| const int | OFF_STATUS = 1 |
| data high orde nibble and status | |
| const int | OFF_CONVERT = 1 |
| start conversion | |
| const int | ADR_WIDTH = OFF_CONVERT + 1 |
| address with | |
Signal masks and shifts | |
| const int | MSK_CTLCHAN = 0x07 |
| mask byte for channel selection | |
| const int | MSK_CTLMPLX = 0x08 |
| mask byte for multiplexer enable | |
| const int | MSK_CTLGAIN = 0x30 |
| mask byte for gain selection | |
| const int | MSK_CTLTRIG = 0x40 |
| mask byte for external trigger | |
| const int | MSK_CTLINTR = 0x80 |
| mask byte for interrupt | |
| const int | MSK_STSBSY = 0x10 |
| mask byte for busy status | |
| const int | MSK_STSEOC = 0x20 |
| mask byte for EOC | |
| const int | MSK_STSINTR = 0x40 |
| mask byte for interrupt | |
| const int | MSK_STSTRIG = 0x80 |
| mask byte for external trigger | |
| const int | MSK_VALMSN = 0x0F |
| mask byte for high order data bits | |
| const int | SHL_CTLCHAN = 0 |
| shift for channel selection | |
| const int | SHL_CTLGAIN = 4 |
| shift for gain selection | |