class Hp34401a

def initialize(adrs=22)
	@gpib=Gpib::new(adrs)
#	@gpib.pad=(adrs); @gpib.sad=0; @gpib.tmo=Gpib::T1s
#	@gpib.open(0); sleep 0.1; #@gpib.ibclr
	@func=function?(); @range=0; @value=0;
end

attr_reader :func
attr_reader :range
attr_reader :value
#attr_accessor :

def reset()
	@gpib.write(sprintf("*RST"))
end

def function(str)
	strs=["VOLT:DC", "VOLT:DC:RAT", "VOLT:AC", "CURR:DC", "CURR:AC", "RES", "FRES", "FREQ", "PER", "CONT", "DIOD"]
	if strs.include?(str)
		@gpib.write(sprintf("FUNC \"%s\"",str))
		@func=str
	else
		print "function is not good.\n"
	end
end
def function?()
	@gpib.write("FUNC?")
	s=@gpib.read(256)
	s.gsub!(/\"/){""}
	return s
end
def set_range(n)
	strs=[0.03, 0.3, 3, 30, 300, 3e3, 3e4, 3e5, 3e6, 3e7]
	if n.class==1.class
		@gpib.write(sprintf("#{@func}:RANG %.2e",strs[n]))
		@range=strs[n]
	else
		@gpib.write(sprintf("#{@func}:RANG:AUTO ON"))
		@range="auto"
	end
end
def set_resolution(str)
	if str=="min"
		@gpib.write(sprintf("#{@func}:RES MIN"))
	elsif str=="max"
		@gpib.write(sprintf("#{@func}:RES MAX"))
	else
		print "resolution is not good.\n"
	end
end
def impedence(str="on")
	if str=="on"
		@gpib.write(sprintf("INPUT:IMPEDENCE:AUTO ON"))
	else
		@gpib.write(sprintf("INPUT:IMPEDENCE:AUTO OFF"))
	end
end


def trigger(str)
	if str=="bus"
		@gpib.write(sprintf("trigger:source BUS"))
	elsif str=="now"
		@gpib.write(sprintf("trigger:source immediate"))
	elsif str=="ext"
		@gpib.write(sprintf("trigger:source external"))
	else
		print "resolution is not good.\n"
	end
end

def read?()
	@gpib.write("READ?")
#	@gpib.write("FETCh?")
	r=@gpib.read(256)
	@value=r.to_f
	return r.to_f
end

def count(n) # for one triger
	@gpib.write(sprintf("SAMPLE:COUNT %d",n))
end
def initiate() # wait triger
	@gpib.write("INITIATE")
end
def points?()
	@gpib.write("DATA:POINTS?")
	r=@gpib.read(256)
	return r.to_i
end
def fetch?()
	@gpib.write("FETCh?")
	r=@gpib.read(256)
	@value=r.to_f
	return r.to_f
end

end #class