# USB-2500 Series

The USB-2500 Series includes the following hardware:

- USB-2523
- USB-2527
- USB-2533
- USB-2537

The USB-2500 Series support the following features.

## Analog Input

Functions

UL: cbAIn(), cbAInScan(), cbALoadQueue(), cbAPretrig()*, cbATrig(), cbFileAInScan()

UL for .NET: AIn(), AInScan(), ALoadQueue(), APretrig()*, ATrig(), FileAInScan()

Python for Windows: a_in(), a_in_scan(), a_load_queue(), a_pretrig(), a_trig()

*Pretrigger capability is implemented in software. PretrigCount must be less than the TotalCount and cannot exceed 100,000 samples. If a trigger occurs while the number of collected samples is less than the PretrigCount, that trigger will be ignored. Requires a call to cbSetTrigger/ SetTrigger for the analog trigger type.

Options

BACKGROUND, BLOCKIO, CONTINUOUS, DMAIO, EXTCLOCK, EXTTRIGGER, HIGHRESRATE

With EXTTRIGGER mode, the first channel in the scan is the analog trigger channel.

Mode

Single-ended and differential

HighChan

USB-2533, USB-2537: 0 to 63 in single-ended mode, 0 to 31 in differential mode

USB-2523, USB-2527: 0 to 15 in single-ended mode, 0 to 7 in differential mode

Rate

Up to 1 MHz

Range

BIP10VOLTS (±10 volts) | BIPPT5VOLTS (±0.5 volts)
BIP5VOLTS (±5 volts) | BIPPT2VOLTS (±0.2 volts)
BIP2VOLTS (±2 volts) | BIPPT1VOLTS (±0.1 volts)
BIP1VOLTS (±1 volts)

Pacing

Hardware pacing, external or internal clock supported.

## Analog Output (USB-2527 and USB-2537 only)

UL: cbAOut(), cbAOutScan(), cbVOut()

UL for .NET: AOut(), AOutScan(), VOut()

Options

ADCCLOCK, ADCCLOCKTRIG, BACKGROUND, CONTINUOUS, EXTCLOCK, NONSTREAMEDIO, SIMULTANEOUS

NONSTREAMEDIO can only be used with the number of samples set equal to the size of the FIFO or less. The FIFO holds 524,288 samples.

HighChan

0 to 3

Rate

1 MHz

Range

Ignored - Not programmable; fixed at BIP10VOLTS (±10 volts)

DataValue

0 to 65,535 (Refer to 16-bit values using a signed integer data type for information on 16-bit values using unsigned integers.)

Pacing

Hardware pacing, external or internal clock supported.

## Digital I/O

Click here to display a table of the port numbers and corresponding bit numbers that are set by the digital I/O functions.

Configuration

Functions

UL: cbDConfigPort()

UL for .NET: DConfigPort()

Python for Windows: d_config_port()

PortNum

FIRSTPORTA, FIRSTPORTB, FIRSTPORTC

Port I/O

Functions

UL: cbDIn(), cbDOut(), cbDInScan(), cbDOutScan()*

UL for .NET: DIn(), DOut(), DInScan(), DOutScan()*

Python for Windows: d_in(), d_out(), d_in_scan(), d_out_scan()

*FIRSTPORTA and FIRSTPORTB must be set for output to use this function. Refer to DIO PortNum in the Hardware Considerations section for more information.

Options

ADCCLOCK, ADCCLOCKTRIG, BACKGROUND, CONTINUOUS, EXTCLOCK, EXTTRIGGER, NONSTREAMEDIO, HIGHRESRATE, WORDXFER

- The EXTTRIGGER option can only be used with the cbDInScan() function. You can use the cbSetTrigger() function to program the trigger for rising edge, falling edge, or the level of the digital trigger input (TTL).
- The WORDXFER option can only be used with FIRSTPORTA.
- The NONSTREAMEDIO, ADCCLOCKTRIG, and ADCCLOCK options can only be used with the cbDOutScan() function.
- The NONSTREAMEDIO option can only be used with the number of samples set equal to the size of the FIFO or less. The FIFO holds 524288 samples.

Rate

12 MHz

PortNum

FIRSTPORTA, FIRSTPORTB, FIRSTPORTC

DataValue

0 to 255

0 to 65,535 using the WORDXFER option with FIRSTPORTA

Bit I/O

Functions

UL: cbDBitIn(), cbDBitOut()

UL for .NET: DBitIn(), DBitOut()

Python for Windows: d_bit_in(), d_bit_out()

PortType

FIRSTPORTA

BitNum

0 to 23

## Counter Input

UL: cbCClear(), cbCIn(), cbCIn32(), cbCConfigScan(), cbCInScan()

UL for .NET: CClear(), CIn(), CIn32(), CConfigScan, CInScan()

Python for Windows: c_clear(), c_in(), c_in_32(), c_config_scan(), c_in_scan

Although cbCIn()/CIn()/c_in() are valid for use with this counter, cbCIn32()/CIn32()/c_in_32() may be more appropriate, since the values returned may be greater than the data types used by cbCIn(), CIn(), and c_in() can handle.

cbCLoad()/cbCLoad32(), CLoad()/CLoad32(), and c_load()/c_load32() only accept Count=0. These functions are used to reset the counter.

Note: Counters on these devices are zero-based (the first counter number is "0").

Rate

6 MHz

CounterNum

0 to 3

Options

BACKGROUND, CONTINUOUS, CTR32BIT, EXTCLOCK, EXTTRIGGER, HIGHRESRATE

You can use the cbSetTrigger() function to program the trigger for rising edge, falling edge, or the level of the digital trigger input (TTL).

Mode

- TOTALIZE: BIT_32, CLEAR_ON_READ, DECREMENT_ON, GATING_ON, LATCH_ON_MAP, STOP_AT_MAX
- ENCODER: ENCODER_MODE_CLEAR_ON_Z_ON, ENCODER_MODE_LATCH_ON_Z, ENCODER_MODE_X1, ENCODER_MODE_X2, ENCODER_MODE_X4
- PERIOD: PERIOD_MODE_BIT_32, PERIOD_MODE_BIT_48, PERIOD_MODE_GATING_ON, PERIOD_MODE_X1000
- PULSEWIDTH: PULSEWIDTH_MODE_BIT_32, PULSEWIDTH_MODE_BIT_48, PULSEWIDTH_MODE_GATING_ON

When using Period and PulseWidth modes, note that the initial period is dependent upon the frequency of the signal being measured, a signal is required in order to latch data into the register, and the first sample in a scan is always zero, since it is not data that has been latched by the measured signal.

When using cbCIn()/CIn() and cbCIn32()/CIn32, PERIOD, PULSEWIDTH, and ENCODER modes are not available.

LoadValue

0 to 65,535

The Visual Basic signed integers guidelines apply when using cbCIn() or CIn() for values greater than 32,767 and when using cbCIn32() or CIn32() for values greater than 2,147,483,647.

## Timer Output

UL: cbTimerOutStart(), cbTimerOutStop()

UL for .NET: TimerOutStart(), TimerOutStop()

Python for Windows: timer_out_start(), timer_out_stop()

TimerNum

0 to 1

Frequency

15.260 Hz to 1.0 MHz

## Triggering

UL: cbSetTrigger()

UL for .NET: SetTrigger()

Python for Windows: set_trigger()

TrigType

TRIGABOVE, TRIGBELOW, TRIGHIGH, TRIGLOW, TRIGPOSEDGE, TRIGNEGEDGE

Digital triggering (TRIGHIGH, TRIGLOW, TRIGPOSEDGE, TRIGNEGEDGE) is not supported for pre-trigger acquisitions (cbAPretrig() function).

Analog triggering (TRIGABOVE, TRIGBELOW) is not supported for the cbDInScan() function and the cbCInScan() function.

Threshold

Analog hardware triggering, 12-bit resolution: 0 to 4,095 (supported for cbAInScan() only)

Analog software triggering, 16-bit resolution: 0 to 65,535 (supported for cbAPretrig() only)

Note: When the cbAInScan() EXTTRIGGER mode is enabled, the first channel in the scan is the analog trigger channel.

## Temperature Input

UL: cbTIn(), cbTInScan(), cbGetTCValues()

UL for .NET: TIn(), TInScan(), GetTCValues()

Python for Windows: t_in(), t_in_scan(), get_tc_values()

Options

NOFILTER

Scale

CELSIUS, FAHRENHEIT, KELVIN

HighChan

0 to 3

## DAQ Input

UL: cbDaqInScan()

UL for .NET: DaqInScan()

Python for Windows: daq_in_scan()

Options

BACKGROUND, BLOCKIO, CONTINUOUS, DMAIO, EXTCLOCK, EXTTRIGGER, HIGHRESRATE

ChanTypeArray

ANALOG, DIGITAL8, DIGITAL16, CTR16, CTR32LOW, CTR32HIGH, CJC, TC, SETPOINTSTATUS

When mixing ANALOG channel types with any other input types, the ANALOG channels should be the first in the list.

Note: For information on associating CJC channels with TC channels, refer to Hardware considerations below.

ChanArray

ANALOG:

- USB-2533, USB-2537: 0 to 63 in single-ended mode, 0 to 31 in differential mode
- USB-2523, USB-2527: 0 to 15 in single-ended mode, 0 to 7 in differential mode

DIGITAL8: FIRSTPORTA, FIRSTPORTB, FIRSTPORTC

DIGITAL16: FIRSTPORTA

CTR16: 0 to 3 counters

CTR32LOW: 0 to 3 counters

CTR32HIGH: 0 to 3 counters

CJC: 0 to 2

TC: 0 to 3

SETPOINTSTATUS: 16-bit port that indicates the current state of the 16 possible setpoints.

ChanTypeArray flag value:

- SETPOINT_ENABLE: Enables a setpoint. Refer to "Setpoints" in Hardware Considerations below for more information.

Rate

Analog: Up to 1 MHz.

Digital: Up to 12 MHz if no analog channel is selected. Otherwise up to 1 MHz.

Counter: Up to 12 MHz if no analog channel is selected. Otherwise up to 1 MHz.

GainArray

ANALOG only; ignore for other ChanTypeArray values.

BIP10VOLTS (±10 volts)

BIP5VOLTS (±5 volts)

BIP2VOLTS (±2 volts)

BIP1VOLTS (±1 volt)

BIPPT5VOLTS (±0.5 volt)

BIPPT2VOLTS (±0.2 volt)

BIPPT1VOLTS (±0.1 volt)

PretrigCount

100,000 max

## DAQ Triggering

UL: cbDaqSetTrigger()

UL for .NET: DaqSetTrigger()

Python for Windows: daq_set_trigger()

TrigSource

TRIG_IMMEDIATE, TRIG_EXTTTL, TRIG_ANALOGHW, TRIG_ ANALOGSW, TRIG_DIGPATTERN, TRIG_COUNTER, TRIG_SCANCOUNT

TrigSense

RISING_EDGE, FALLING_EDGE, ABOVE_LEVEL, BELOW_LEVEL, EQ_LEVEL, NE_LEVEL

TrigEvent

START_EVENT, STOP_EVENT

## DAQ Setpoint

UL: cbDaqSetSetpoints()

UL for .NET: DaqSetSetpoints()

Python for Windows: daq_set_setpoints()

SetpointFlagsArray

SF_EQUAL_LIMITA, SF_LESSTHAN_LIMITA, SF_GREATERTHAN_LIMITB, SF_OUTSIDE_LIMITS, SF_HYSTERESIS, SF_UPDATEON_TRUEONLY, SF_UPDATEON_TRUEANDFALSE

SetpointOutputArray

SO_NONE, SO_FIRSTPORTC, SO_TMR0, SO_TMR1

Also available for USB-2527 and USB-2537:

SO_DAC0, SO_DAC1, SO_DAC2, SO_DAC3

LimitAArray

Any value valid for the associated input channel.
Ignored for SF_GREATERTHAN_LIMITB

LimitBArray

Any value valid for the associated input channel and less than LimitA.
Ignored for SF_EQUAL_LIMITA, SF_LESSTHAN_LIMITA

Output#Array

For SetpointOutputArray = SO_NONE: Ignored

For SetpointOutputArray = SO_FIRSTPORTC: 0 to 65,535

For SetpointOutputArray = SO_TMR#: 0 (to disable the timer) or 15.26 to 1,000,000 (to set the output frequency)

For SetpointOutputArray = SO_DAC#: Voltage values between –10 and +10

OutputMask#Array

For SetpointOutputArray = SO_FIRSTPORTC: 0 to 65,535

For SetpointOutputArray = all other values: Ignored

SetpointCount

0 (to disable setpoints) to 16

## DAQ Output (USB-2527 and USB-2537 only)

UL: cbDaqOutScan()

UL for .NET: DaqOutScan()

Python for Windows: daq_out_scan()

Options

ADCCLOCK, ADCCLOCKTRIG, BACKGROUND, CONTINUOUS, EXTCLOCK, NONSTREAMEDIO, SIMULTANEOUS

ChanType

ANALOG, DIGITAL16

ChanArray

ANALOG: 0 to 3

DIGITAL16: FIRSTPORTA (FIRSTPORTB must be configured as an output)

Rate

ANALOG: Up to 1 MHz

DIGITAL16: Up to 12 MHz (system-dependent) if no analog channel is selected. Otherwise up to 1 MHz.

Range

Ignored

## Configuration

This hardware supports device detection with the API. Refer to the InstaCal, API Detection, or Both? section for information about whether to use InstaCal or the API to detect and configure hardware.

#### InstaCal

Factory serial number

Listed as Serial # (read only)

Input mode

Input Mode drop-down combo box for single-ended or differential.

Calibration coefficients

Calibration Coefficients drop-down combo box.

Input pacer clock edge

XAPCR Edge drop-down combo box.

Input pacer clock direction

XAPCR Pin Direction drop-down combo box.

Output pacer clock edge

XDPCR Edge drop-down combo box.

Output pacer clock direction

XDPCR Pin Direction drop-down combo box.

ADC settling time

ADC Settling Time drop-down combo box.

Rejection frequency

Reject Frequency drop-down combo box.

No. samples/average

No. Samples/Avg drop-down combo box.

Thermocouple type

Chanx drop-down combo box for channel 0 to 3.

#### Programmable API Functions

Factory serial number

UL: cbGetConfigString()

ConfigItem = BIDEVSERIALNUM

UL for .NET: GetDeviceSerialNum()

Python for Windows: get_config_string()

config_item = DEVSERIALNUM

Input mode

UL: cbAInputMode()

UL for .NET: AInputMode()

Python for Windows: a_input_mode

Calibration coefficients table

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BICALTABLETYPE

ConfigVal = CAL_TABLE_FACTORY, CAL_TABLE_FIELD

UL for .NET: GetCalTableType(), SetCalTableType()

Python for Windows: get_config(), set_config()

config_item = CALTABLETYPE

config_val = FACTORY, FIELD

Input pacer clock edge

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BIEXTINPACEREDGE

ConfigVal = EXT_PACER_EDGE_RISING, EXT_PACER_EDGE_FALLING

UL for .NET: GetExtInPacerEdge(), SetExtInPacerEdge()

Python for Windows: get_config(), set_config()

config_item = EXTINPACEREDGE

config_val = ExtPacerEdge enum

Input pacer clock direction

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BIINPUTPACEROUT

ConfigVal = ENABLED, DISABLED

UL for .NET: GetInputPacerOut(), SetInputPacerOut()

Python for Windows: get_config(), set_config()

info_type = BOARDINFO

config_item = INPUTPACEROUT

config_val = State enum

Output pacer clock edge

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BIEXTOUTPACEREDGE

ConfigVal = EXT_PACER_EDGE_RISING, EXT_PACER_EDGE_FALLING

UL for .NET: GetExtOutPacerEdge(), SetExtOutPacerEdge()

Python for Windows: get_config(), set_config()

config_item = EXTOUTPACEREDGE

config_val = ExtPacerEdgeType

Output pacer clock direction

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BIOUTPUTPACEROUT

ConfigVal = ENABLED, DISABLED

UL for .NET: GetOutputPacerOut(), SetOutputPacerOut()

Python for Windows: get_config(), set_config()

config_item = OUTPUTPACEROUT

config_val = ENABLED (output), DISABLED

ADC settling time

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BIADCSETTLINGTIME

ConfigVal = SETTLE_DEFAULT, SETTLE_1us, SETTLE_5us, SETTLE_10us, SETTLE_1ms

UL for .NET: GetAdSettlingTime(), SetAdSettlingTime()

Python for Windows: get_config(), set_config()

config_item = ADCSETTLETIME

config_val = SettleTime enum

Rejection frequency

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BITEMPREJFREQ

ConfigVal = 0 (off), 50 (50 Hz), 60 (60 Hz)

UL for .NET: GetTempRejFreq(), SetTempRejFreq()

Python for Windows: get_config(), set_config()

config_item = TEMPREJFREQ

config_val = 0, 50, 60

No. samples/Average

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BITEMPAVG

ConfigVal = 1 to 16384 (Rejection Frequency is off), 16 to 16384 (Rejection Frequency is on)

UL for .NET: GetTempAvg(), SetTempAvg()

Python for Windows: get_config(), set_config()

config_item = TEMPAVG

config_val = 1 to 16384 (if the TEMPREJFREQ rejection frequency is off (0), 16 to 16384 (if the TEMPREJFREQ rejection frequency is on (50 or 60)

Thermocouple type

UL: cbGetConfig(), cbSetConfig()

ConfigItem = BICHANTCTYPE

ConfigVal = TC_TYPE_J, TC_TYPE_K, TC_TYPE_S, TC_TYPE_R, TC_TYPE_B, TC_TYPE_E, TC_TYPE_T, TC_TYPE_N

UL for .NET: GetChanTcType(), SetChanTcType()

Python for Windows: get_config(), set_config()

config_item = CHANTCTYPE

config_val = TcType enum

## Hardware considerations

##### Associating CJC channels with TC channels

The TC channels must immediately follow their associated CJC channels in the channel array. For accurate thermocouple readings, associate CJC0 with TC0, CJC1 with TC1 and TC2, and CJC2 with TC3.

The board must be configured for differential inputs when using thermocouples.

##### Channel count

For input and output scans, the count must be set to an integer multiple of the number of channels or a BADCOUNT error is returned.

##### Sampling and update rates

Sampling and update rates are system-dependent. Data overruns/underruns may occur with higher sampling rates when using BACKGROUND and CONTINUOUS modes. To avoid this, use a larger buffer/count size, or use NONSTREAMEDIO mode, if supported.

The minimum size buffer is 256 for cbAOutScan(), cbDInScan(), and cbDOutScan(). Values less than 256 result in a BADBUFFERSIZE error.

##### HIGHRESRATE

Specify the HIGHRESRATE scan option to acquire data at a high resolution rate. When specified, the rate at which samples are acquired is in "samples per 1,000 seconds per channel".

##### Settling time

For most applications, settling time should be left at the default value of 1 µs. However, if you are scanning multiple channels and one or more channels are connected to a high impedance source, you may get better results by increasing the settling time. Keep in mind that increasing the settling time reduces the maximum acquisition rate. You can set the time between A/D conversions with the ADC Settling Time option in InstaCal. Select between 1 µs, 5 µs, 10 µs, or 1 ms.

##### Setpoints

You enable setpoints with the SETPOINT_ENABLE flag. This flag must be OR'ed with the ChanTypeArray argument values. You set the setpoint criteria with cbDaqSetSetpoints()/DaqSetSetpoints(). The number of channels set with the SETPOINT_ENABLE flag must match the number of setpoints set by the SetpointCount argument (cbDaqSetSetpoints()/DaqSetSetpoints()).

##### Output non-streamed data to a DAC output channel

With NONSTREAMEDIO mode, you can output non-streamed data to a specific DAC output channel. The aggregate size of the data output buffer must be less than or equal to the size of the internal data output FIFO in the device. The FIFO holds 524288 samples. This allows the data output buffer to be loaded into the device's internal output FIFO. Once the sample updates are transferred or downloaded to the device, the device is responsible for outputting the data. You can't change the output buffer once the output begins.

##### Trigger DAC output operations with the ADC clock

Specify the ADCCLOCK option to trigger a data output operation upon the start of the ADC clock.

##### DIO PortNum

For cbDOutScan()/DOutScan() and cbDaqOutScan()/DaqOutScan(), FIRSTPORTA and FIRSTPORTB are treated as one 16-bit port. These functions can only be used with FIRSTPORTA. You must configure both FIRSTPORTA and FIRSTPORTB for output using the cbDConfigPort() function.

##### Synchronous scanning with multiple boards

You can operate up to four USB-2500 Series boards synchronously by setting the direction of the A/D and D/A pacer pins (XAPCR or XDPCR) in InstaCal.

On the board used to pace each device, set the pacer pin that you want to use (XAPCR or XDPCR) for Output. On the board(s) that you want to synchronize with this board, set the pacer pin that you want to use (XAPCR or XDPCR) for Input.

Set the direction using the XAPCR Pin Direction and XDPCR Pin Direction settings on the InstaCal configuration dialog. If you have an older version of InstaCal, these settings might be labeled "ADC Clock Output" (set to Enabled to configure XAPCR for output) or "DAC Clock Output" (set to Enabled to configure XDPCR for output).

Wire the pacer pin configured for output to each of the pacer input pins that you want to synchronize.

##### Quadrature encoder operations

To configure a counter channel as a multi-axis quadrature encoder, use the cbCConfigScan()/CConfigScan()/c_config_scan() Mode values to set a specified counter to encoder mode, set the encoder measurement mode to X1, X2, or X4, and then set the count to be latched either by the internal "start of scan" signal (default) or by the signal on the mapped channel.

You can optionally perform the following operations:

- Enable gating, so that the counter is enabled when the mapped channel to gate the counter is high. When the mapped channel is low, the counter is disabled but holds the count value.
- Enable "latch on Z" to latch counter outputs using the Encoder Z mapped signal.
- Enable "clear on Z" so that the counter is cleared on the rising edge of the mapped (Z) channel. By default, "clear on Z" is disabled, and the counter is not cleared.

##### Asynchronous reads

The CConfigScan() method's Bit32 counter mode option only affects counter resolution for asynchronous calls (CIn() and CIn32()), and only when the counter is configured for StopAtMax.
This mode is recommended for use only with CIn32(). Using the Bit32 option with CIn() is not very useful, since the value returned by CIn() is only 16 bits. The effect is that the value returned by CIn() rolls over 65,535 times before stopping.

##### PERIOD and PULSEWIDTH counter modes

When using Period and PulseWidth modes, note that the initial period is dependent upon the frequency of the signal being measured, a signal is required in order to latch data into the register, and the first sample in a scan is always zero, since it is not data that has been latched by the measured signal.

##### Concurrent operations

Concurrent operations are not allowed. If you invoke a function while another function is already running on the device, the ALREADYACTIVE error is returned.