Introducing Message-Based DAQ

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Note: Click Send Message after changing the type of data to return. API message reference Click on a component link below to go the text messages, device responses, and property values supported by each DAQ component. AI AISCAN AITRIG DIO CTR DEV AO Page 34 of 43
DAQFlex Firmware Architecture This document contains the specifications for the interface between the DAQFlex Software API and the DAQFlex firmware that is required to create Message-Based DAQ (MBD) applications. The DAQFlex firmware uses a String Message Based Interface (SMBI) to communicate with DAQFlex Series hardware. Refer to the API message reference for information about the DAQ components and string messages supported by the DAQFlex API. Refer to the Hardware Reference section for information on the commands and property values that are supported by DAQFlex Series devices. SMBI data types Special formatting characters are retuned with RAW data (except streaming data from bulk transfers) to indicate the following data types: • char[64]: String data in a character array • uint8: unsigned 8-bit value • uint16: unsigned 16-bit value • uint32: unsigned 32-bit value • float32: float 32-bit value Communication mechanism The device enumerates as a USB device using an MCC driver. Control transfers • Control transfers to endpoint 0 are used to communicate with the device. • The control transfer maximum buffer size is 64 bytes. • The control transfers are vendor transfers. • The command code is in the bRequest field. ¡ SMBI uses the 0x80 data type for strings, and the 0x81 data type for RAW data, when supported. • Parameters passed for OUT control transfers are sent during the data stage. • The SMBI data stage will return RAW data, LSB first. The DEV component message "DEV:DATATYPE=ENABLED" specifies whether raw data is enabled or disabled for returned data. When using "DEV:DATATYPE=ENABLED" the first byte indicates the data type returned. Refer to the Notes below for more information. • The amount of data being transferred must be specified in the wLength field. SMBI control messages • Invalid OUT messages have a STALL response, and the IN response is "INVALID", RAW return is a 0 length data packet. • Default return for an IN request before an OUT results in a return message of "NO COMPONENT SET" • Valid messages have an ACK response. A valid response to an IN request is in the form of a string. RAW data is only returned for supported messages. • A RAW data return for an invalid message is a 0 length packet, unless "DEV:DATATYPE=ENABLE" where it will return a 1 byte packet with 0xFF as the value indicating an error/invalid. Miscellaneous • Bulk transfers from endpoint 1 IN are used for analog input scans. Data is in RAW format and "DEV:DATATYPE" has no impact on the data. Note:Refer to device-specific information to determine whether bulk transfer components are supported. • Multi-byte data, for example integers, are sent LSB first. Page 35 of 43
Page 11 and 12: Analog input scan operation C# Visu
Page 13 and 14: DEV Sets and gets device property v
Page 15: RESET Message Device response Descr
Page 19 and 20: SCALE 1 Message Device response Des
Page 21 and 22: SAMPLES Message Device response Des
Page 23: LOWCHAN Message Device response Des
Page 26 and 27: CAL 1 Message Device response Descr
Page 28 and 29: AO Sets and gets property values fo
Page 30 and 31: DIO Sets and gets property values f
Page 42 and 43: Programming and developing applicat

Introducing Message-Based DAQ

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