Keithley 708B Reference Manual page 28

Models 707B and 708B Switching Matrix Reference Manual
Controlling digital I/O lines
Digital I/O lines are primarily intended for use with a device handler for limit testing. They can also be
used for other purposes, such as controlling external logic circuits. You can control lines either from
the front panel or over a remote interface.
You can use digital I/O lines for both input and output.
You must write a 1 to all digital I/O lines that are to be used as inputs.
The trigger mode for the line must be set to digio.TRIG_BYPASS in order to use the line for digital
I/O. See Trigger model
The digital I/O lines are not affected by any reset. However, they are affected by a power cycle.
To set digital I/O values from the front panel:
1. Press the MENU key, select DIGIO. Press the ENTER key or press the navigation wheel.
2. Select DIGIO-OUTPUT. Press the ENTER key or the navigation wheel.
3. Set the decimal value as required to set digital I/O lines. The range is 0 to 16,383 (see
bit weighting
4. Press the EXIT key as needed to return to the main menu.
To write protect specific digital I/O lines from the front panel:
1. Press the MENU key, then select DIGIO. Press the ENTER key or the navigation wheel.
2. Select WRITE-PROTECT. Press the ENTER key or the navigation wheel.
3. Set the decimal value as required to write protect digital I/O lines. The range is 0 to 16,383 (see
Digital I/O bit weighting
4. Press the EXIT key as needed to return to the main menu.
5. To remove write protection, repeat the above steps, but enter the original value in step 3.
To set digital I/O values from the remote communication interface:
Send the digio.writeport()
To write-protect specific digital I/O lines from the remote communication interface:
Send the digio.writeprotect
Digital I/O bit weighting
Bit weighting for the digital I/O lines is shown in the following table.
707B-901-01 Rev. A / August 2010
(on page 3-1) for information.
(on page 2-9)). Press the ENTER key or the navigation wheel.
(on page 2-9)). Press the ENTER key or the navigation wheel.
(on page 7-65) command.
(on page 7-66) command.
NOTE
NOTE
NOTE
Section 2: General operation
Digital I/O
2-9