Measurement Computing DAQFlex - Manual (Page 34)

DAQFlex Message-based Firmware Specification Hardware Reference – USB-1608G Series
34
 2 analog output channels, numbered 0 to 1 (USB-1608GX-2AO only)
Analog output range is fixed at ±10V.
 1 digital port (8 bits)
Each bit is individually configurable as input or output.
 1 timer output channel
 1 external trigger input
 External pacer input/output
This feature allows multiple devices to acquire synchronized samples.
 1024 bytes of nonvolatile EEPROM memory; used for storing configuration information, calibration
data, and user data.
 RATE takes a float value
An error is generated if the input scan rate requested is less than the device's minimum sampling
rate or greater than the device's maximum sampling rate.
 Calibration operations
o AICAL:LOCK locks the AICAL component from performing calibration operations on the analog
inputs. In order to calibrate the analog inputs, you must first unlock the component using the
AICAL:UNLOCK message.
o AOCAL:LOCK locks the AOCAL component from performing calibration operations on the analog
outputs. In order to calibrate the analog outputs, you must first unlock the component using
the AOCAL:UNLOCK message.
Refer to Analog input calibration messages and Analog output calibration messages for the
calibration messages provided by the firmware.
 Bulk transfers:
o Bulk transfers from endpoint 6 IN are used for analog input scans. Bulk transfers to endpoint
2 OUT are used for analog output scans.
o The bulk in and bulk out max packet sizes are 512 bytes when enumerated as a high-speed
device and 64 bytes when enumerated as a full-speed device.
o The bulk transfer size must be a multiple of the USB maximum bulk packet size.
o Bulk transactions are complete when a packet is sent that is < the max packet size. When
sending an integer multiplier of the max packet size of data during a transaction, include an
empty packet to indicate the end of the transaction.