hp3561_set_source_atten (ul_scopes)

	status.i4.v = hp3561_set_source_atten(dev_address.i4.v, x_value.r4.r, 
					y_value.r4.r)

	Identifies the HP3561 instrument with a text string of make, model and
	version.


	dev_address	address of scope; A previos call to gpib_select()
			will have to be made to establish communication 
			to correct VME.
	atten		The current source attenuation of the analyzer
	up_arrow	A TRUE value settings will increase the attenuator 
			by 1.5 db steps automaticaly.
	down_arrow	A TRUE value settings will decrease the attenuator 
			by 1.5 db steps automaticaly.

	This function returns ACNET status values as follows:

	CBS_OK			success
	CBS_INVARG		invalid device address
	otherwise		GAS error

	This function requires the following include files:

	ul_scopes_h:hpdefs_h

	Related functions:

	hp3561_get_waveform, hp3561_init, hp3561_marker_to_peak, 
	hp3561_read_marker, hp3561_read_source_values, hp3561_read_values, 
	hp3561_set_source_atten, hp3561_source_on, hp3561_source_window