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jvs:cigal:manual:chapter7:meascomp

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 Measurement Computing Inc. using their Universal Library software interface. We have found their 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)

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 Configure(1) program to put the appropriate Init command into the automatic 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 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 4 channel pin-out and 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 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

Using Universal Library routines in CIGAL

CIGAL's CALL function can be used to run some Measurement Computing's Universal Library routines directly. See MeasCompPrimitives for details.

See Also:
Initialize, Configure, ADC
USB-1208FS,Measurement Computing Inc.,Universal Library User Guide

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jvs/cigal/manual/chapter7/meascomp.txt · Last modified: 2014/08/04 16:03 (external edit)