**CIGAL Reference Manual, Chapter 7 (Hardware): Measurement Computing Device**



=====MEASCOMP - Measurement Computing USB Analog/Digital interface device=====
**usage: init meascomp boardnum nachans arev vrange a0 drev dout bits dports **

CIGAL supports data I/O via the low-cost USB port data acquisition devices manufactured by [[http://www.measurementcomputing.com|Measurement Computing Inc.]] using their Universal Library software interface. We have found their [[http://www.mccdaq.com/usb-data-acquisition/USB-1208FS%20.aspx|USB-1208FS]] device to be particularly capable and cost-effective.  

INIT command arguments:
  init meascomp boardnum nachans arev vrange a0 drev dout bits dports 
  defaults:         0       8     0    1/0 2048  0   255   8     1

  Boardnum - Unit device number
  Nachans -  Number of Analog input channels 4/8 (see hardware config file: CB.CFG)
  Arev - Reverse analog data on input
  Vrange - Analog voltage range: 0= +-5v, 1= +-10v (must be 1 if 8-chan)
  A0 - Zero volts A/D digital offset
  Drev - Reverse digital data on i/o 
  Dout - Channel mask indicating digital output bits
  Bits - Number of channels (bits) per digital ports
  Dports - Number of digital ports (first port is output)

[[jvs:cigal:manual:chapter7:meascompinstall|Installing MeasComp Device]]

**CIGAL configuration**

In order for CIGAL to use this device it must be told to look for it via its **init meascomp** command. Usually that is done by using the CIGAL [[jvs:cigal:manual:chapter1:configure|Configure(1)]] program to put the appropriate [[jvs:cigal:manual:chapter2:initialize|Init]] command into the automatic [[jvs:cigal:manual:chapter1:startup|start-up]] scripts. To do so, simply start CIGAL, enter the **configure** command, and click yes when asked if you have a Measurement Computing device.  (Alternatively you could simply edit your **userconfig.imp** or **sysconfig.imp** file if it already exists and manually change the commands in the initialize section.)

Keep in mind that analog input hardware lines are assigned to CIGAL ADC channel numbers in the order that the analog hardware devices were initialized. See [[jvs:cigal:manual:chapter7:adc|ADC(7)]] for more information.

**Connecting analog signals to the MeasComp device**

Measurement Computing's USB-1208FS device has 8 analog input lines, which can be configured as 4 differential inputs or 8 single-ended inputs.  The default configuration is for 4 differential inputs. The cable connections for each configuration can be seen in [[jvs:cigal:manual:chapter7:meascomp4chan|4 channel pin-out]] and [[jvs:cigal:manual:chapter7:meascomp8chan|8 channel pin-out]].

**Connecting digital signals to the MeasComp device**

Measurement Computing's USB-1208FS device has 16 digital lines, which can be configured as inputs or output signals.  The default configuration is for 8 input lines (PortA) and 8 output lines (PortB). The connections for digital input and output lines can be seen in [[jvs:cigal:manual:chapter7:meascomp8chan|pin-out]].

**Hardware specifications**

The users manual for the USB-1208FS hardware is available from the manufacturer at:\\
[[http://www.measurementcomputing.com/PDFManuals/usb-1208fs.pdf|http://www.measurementcomputing.com/PDFManuals/usb-1208fs.pdf]]

**Using Universal Library routines in CIGAL**

CIGAL's [[jvs:cigal:manual:chapter2:call|CALL]] function can be used to run some Measurement Computing's Universal Library routines directly.  See [[jvs:cigal:manual:chapter7:meascompprims|MeasCompPrimitives]] for details.

**See Also:**\\
[[jvs:cigal:manual:chapter2:initialize|Initialize]],
[[jvs:cigal:manual:chapter1:configure|Configure]],
[[jvs:cigal:manual:chapter7:adc|ADC]]\\
[[http://www.mccdaq.com/usb-data-acquisition/USB-1208FS%20.aspx|USB-1208FS]],[[http://www.measurementcomputing.com|Measurement Computing Inc.]],[[http://www.measurementcomputing.com/PDFmanuals/sm-ul-user-guide.pdf|Universal Library User Guide]]

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