Invert in – Measurement Computing Digital232 User Manual
Page 36

Section 3
Command Descriptions
3.14
Invert In
The Invert command is used to change the polarity of the handshake and data
lines. At power up all handshake and control lines are active high (logic one = + 5
volts). The Invert command can selectively change the polarity of each of the
handshake lines, and of the data lines. If multiple Invert commands are contained
within the same string, then an Execute command (X) should be included between
each Invert command. An alternative is to add the values of each Invert command
desired, and send one command with the sum of the desired commands. The Invert
commands are Ored together as received. To delete any one command, it is necessary
to program the default mode I0, then re-program the desired commands.
I0
All control lines are active high, all data lines are high true.
I1
Inhibit output is active low
I2
Trigger output is active low
I4
Data Strobe output is active low
I8
Clear output is active low
I16
Data is low true
I32
EDR input is falling-edge sensitive
I64
Service input is falling-edge sensitive
Example:
@
reset the Digital 232
I32XI64
select EDR and Service input as
falling-edge sensitive
note:
I96
performs the same function as above