Introducing Message-Based DAQ

AISCAN
Sets and gets property values when scanning analog input channels.
Properties
XFRMODE, RATE, SAMPLES, BUFSIZE, EXTPACER, HIGHCHAN, LOWCHAN, TRIG, RANGE, QUEUE, START, STOP, STATUS, COUNT,
CAL, SCALE
The tables below list the messages used to get and set device parameters, the device response to each message, a description of the
message, and the variable(s) the message may contain.
Note: Refer to the device-specific information in the Hardware Reference section for the component properties and commands
supported by each DAQ device.
XFRMODE
Message Device response Description
"AISCAN:XFRMODE=value" "AISCAN:XFRMODE" Sets the transfer mode for analog input scan
data.
value = SINGLEIO or BLOCKIO
Example: "AISCAN:XFRMODE=BLOCKIO"
"?AISCAN:XFRMODE" "AISCAN:XFRMODE=value" Returns the transfer mode that is set for the
scan.
value = SINGLEIO or BLOCKIO
RATE
Message Device response Description
"AISCAN:RATE=value" "AISCAN:RATE" Sets the A/D sampling rate in Hz for each
channel.
value = 0 to N
Example: "AISCAN:RATE=1000"
• If value is less than the device's minimum sampling rate, then the minimum rate is used. If value is greater than the
device's maximum sampling rate, then the device's maximum sampling rate is used.
• It is recommended to check the actual scan rate set using the "?AISCAN:RATE" query after setting the RATE.
"?AISCAN:RATE" "AISCAN:RATE=value" Returns the A/D sampling rate in Hz for each
channel.
value = a value between the minimum and
maximum rate that the device is capable of.
• The value returned may not match the value requested using the "AISCAN:RATE=value" message due to device
limitations.
• If the value returned is at or near the device's maximum sampling rate, then sending other messages to the device
should be kept to a minimum. Otherwise, there is a potential for a data overrun to occur. A data overrun occurs when
the device fills its buffer with data faster than it is read back.
Page 20 of 43