Omega Vehicle Security 1400 manual Set Counts, or Select Blocks, PRINT#1,OUTPUT07N0 N2

Appendix A API Commands

Y- Set Counts, or Select Blocks

TYPE	Acquisition
EXECUTION	Deferred
SYNTAX	Ypre,post,	When in Normal mode of data acquisition, set acquisition counts where pre
	stop	is the pre-trigger count, post is the post-trigger count and stop is the
		post-stop count.
	Y0,count,0	When in High-speed, single-channel mode (burst mode), set count; where
		count is the number of 256 sample blocks to be collected
	Y?	Query current acquisition count selections.

DESCRIPTION

Normal Mode

When in Normal mode for data acquisition, the Set Counts (Y) command can be used to select a pre-trigger, post-trigger, and post-stop count to define the size of the acquisition. The pre-trigger count cannot exceed the memory size, but the post-trigger count can. If the post-trigger count exceeds the memory size, it is the responsibility of the IEEE 488 controller to deplete the FIFO buffer as the data is being collected, or a buffer overrun error will occur. A Post Stop Event Count can also be associated with an acquisition to collect a counted amount of samples after the Stop Event occurs.

If a trigger is encountered before the pre-trigger count is satisfied, the unit will trigger but have fewer than the specified pre-trigger count in its buffer. The Buffer Status String (U6) command can be used to query the box for the size of the pre-trigger. Although normal pre-trigger scans are acquired as soon as the acquisition is armed, they are not available or valid until the start trigger event occurs.

Note: The unit can be configured to have different timebases for its pre-and post-trigger states. When the user- specified trigger condition is satisfied, the unit goes from the pre-trigger to the post-trigger state, changing its timebase, if configured to do so. Refer to the Continuous, Gap-Free Acquisition with Two Timebases in Appendix B for more information.

High-Speed, Single-Channel Mode

When in High-speed,single-channel mode (burst mode); count (see syntax) is used to select the number of 256 sample blocks to collect. Valid values for count are as follows:

	System Memory		Post-Trigger Count*
	256 Kbytes		2 to 512
	1 Megabytes		2 to 2048
	4 Megabytes		2 to 8192
	8 Megabytes		2 to 16384
*In each case, the number assigned for block count must be a power of 2.
EXAMPLE for Normal Mode
PRINT#1, “OUTPUT07;Q1,0,1,1,1X”		‘ Set the reading separator flag ON
PRINT#1, “OUTPUT07;F0,0X”		‘ Data format is engineering units, degrees C
PRINT#1,"OUTPUT07;C1-4,1X"		‘ Configure channels 1 - 4 as T/C type J
PRINT#1,"OUTPUT07;I00:00:01.0,		‘ Configure scan interval
00:00:00.1”
PRINT#1,"OUTPUT07;Y100,1000,50X"		‘ Configure acquisition counts
PRINT#1,"OUTPUT07;N0 N2 X"		‘ Configure Event Status Register Bit (ESB) to be set when
			pre-trigger count is satisfied
PRINT#1,"OUTPUT07;T1,8,0,0X"		‘ Configure acquisition, start trigger is Trigger On (@)
			command, stop trigger is Counts
S% = 0		‘ Wait for the pre-trigger count to become satisfied
WHILE (S% AND 32) = 0
PRINT#1,"SPOLL07"
INPUT#2,S%
WEND
PRINT#1,"OUTPUT07;N0 N1 X"		‘ Configure ESB to be set when acquisition is complete
S% = 0		‘ Wait for the acquisition to become complete
WHILE (S% AND 32) = 0
PRINT#1,"SPOLL07"
INPUT#2,S%
WEND
PRINT#1,"OUTPUT07;U6X"		‘ Get Buffer Status String
PRINT#1,"ENTER07"		‘ Retrieve the response
INPUT A$		‘ Screen shows 0000001,0001151,-0000100,
		10:02:02.0,04/24/93,00001000,

10:23:30.0,04/24/93,00001050,01

‘ Indicates that 100 pre-trigger scans were acquired 1000 post-trigger scans were acquired and 50 post-stop scans were acquired

ChartScan User’s Manual A-63