User manual

IEEE-488 Reference
2001-900-01 Rev. K / August 2010 4-163
:SOURce:TTL3:[LEVel] <b> Control digital output line #3
:SOURce:TTL4:[LEVel] <b> Control digital output line #4
Parameters <b> = 1 or ON Set output line true
= 0 or OFF Set output line false
Formats :sour:ttl <b>
:sour:ttl2 <b>
:sour:ttl3 <b>
:sour:ttl4 <b>
Defaults Power-up OFF (all lines)
*RST No effect
:SYSTem:PRESet No effect
Query :LEVel]? Query logic level of specified line
Short-form formats: :sour:ttl? :sour:ttl2?
:sour:ttl3? :sour:ttl4?
Response message: 0 (false) or 1 (true)
Description These commands are used to set the logic levels for the digital output port. The actual level (high or low)
of a digital output line depends on its programmed polarity (see Output subsystem). If the polarity of a
line is active-high, then that line will be high when it is set to be true (1 or ON), and low when it is set to
be false (0 or OFF). Conversely, if polarity is active-low, the line will be low when it is set to be true, and
high when it is set to be false.
Programming example 10 OUTPUT 716; “:sour:ttl on; ttl?”
20 ENTER 716; A$
30 PRINT A$
40 END
Line 10 Sets output line #1 to true, and then queries the state of the output line.
Line 20 Addresses the Model 2001 to talk.
Line 30 Displays the state of output line #1 (1; on).
4.21 :STATus subsystem
The STATus subsystem is used to control the status registers of the Model 2001. These registers and the
overall status structure is explained in paragraph 4.6.
The commands in this subsystem are summarized in Table 4-28.