Keithley 2651A Reference Manual page 194

Model 2651A High Power System SourceMeter® Instrument Reference Manual
Digital I/O bit weighting
Bit weighting for the digital I/O lines is shown in the following table.
Digital bit weight
Line # Bit
1 B1
2 B2
3 B3
4 B4
5 B5
6 B6
7 B7
8 B8
9 B9
10 B10
11 B11
12 B12
13 B13
14 B14
Remote digital I/O commands
Commands that control and access the digital I/O port are summarized in the following table. See
Remote Commands
for decimal and hexadecimal values used to control and access the digital I/O port and individual
lines. Use these commands to trigger the Model 2651A using external trigger pulses applied to the
digital I/O port, or to provide trigger pulses to external devices.
Use these commands to perform basic steady-state digital I/O operations such as reading and writing
to individual I/O lines or reading and writing to the entire port.
The digital I/O lines can be used for both input and output. You must write a 1 to all digital I/O lines
that are to be used as inputs.
Remote digital I/O commands
Command
digio.readbit(bit)
digio.readport()
digio.writebit(bit, data)
digio.writeport(data)
digio.writeprotect = mask
2651A-901-01 Rev. A / March 2011
Decimal weighting Hexadecimal weighting
1 0x0001
2 0x0002
4 0x0004
8 0x0008
16 0x0010
32 0x0020
64 0x0040
128 0x0080
256 0x0100
512 0x0200
1024 0x0400
2048 0x0800
4096 0x1000
8192 0x2000
(on page 5-1) for complete details on these commands. See the following table
Description
Read one digital I/O input line
Read digital I/O port
Write data to one digital I/O output line
Write data to digital I/O port
Write protect mask to digital I/O port
NOTE
Section 3: Functions and features
3-87