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Omega Speaker Systems 8 Channel Thermocouple USB Data Acquisition Module TC-08 User Manual

Page 13

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Technical reference

9

Example

The following code is a fragment of a C application demonstrating how to use
Streaming mode with the USB TC-08 driver:

//==================================================
// Setting up and running the unit in Streaming mode
//==================================================

usb_tc08_set_mains

(handle,

0

);

// use 50Hz mains noise rejection

for

(channel =

0

; channel <

9

; channel++)

{

// set each channel up as a type K thermocouple

// channel 0 is the cold junction and will be enabled

// by setting the third argument to anything other than ' '

usb_tc08_set_channel

(handle, channel,

'K'

);

}

// find out how fast the unit can sample in its current setup state

minimum_interval =

usb_tc08_get_minimum_interval_ms

(handle);

usb_tc08_run

(handle, minimum_interval);

// sample as fast as possible

// not required (just illustrates that the application
// can be idle while the driver collects the readings)

Sleep(

10000

);

// use a two dimensional array with an array of readings for each
channel
// In a real application, this would be a nested loop to regularly poll
// the unit for readings

for

(channel =

0

; channel <

9

; channel++)

{
no_of_readings =

usb_tc08_get_temp

( handle,

&reading_buffer[channel],
×_buffer[channel],
buffer_length,
&overflows[channel],
channel,

0

,

// degrees Celsius units

0

);

// do not fill missing readings

}

// finished polling, now do something with the readings
// if overflows[channel] is high, then one of the readings
// in reading_buffer[channel] has exceeded the input range
// of the USB TC-08

// only stop the unit when we've completely finished streaming

usb_tc08_stop

(handle);

Note: You should close down all other applications while you are performing any
timing-critical data logging tasks. Check that the Windows scheduler does not have
any activities planned during the logging session.