Keithley 7037, Instruction Manual

Page: 39 / 72

Operation
5-6
Reading input channels
Input channels are read from the READ-I/O-CARD option
of the CARD CONFIG MENU of the mainframe. This menu
is accessed by pressing the CARD key. In this “read input
channels” display mode, the mainframe displays the real-
time state of each input channel.
Input channels use positive true logic but can be configure
to pull up or pull down. Open inputs will read high (on) if
inputs are configured for pull up. Conversely, open inputs
will read low (off) when configured for pull down. To config
ure pull-up resistance, refer to Section 4.
Perform the following steps to configure the mainframe to
display the digital input channels.
1. Press the CARD CONFIGURATION key to display the
CARD CONFIG MENU.
2. Use the
§
and
©
keys to place the cursor on READ-I/
O-CARD and press ENTER.
Model 7001 mainframe — The real-time state (on or
off) of each input channel is provided on the first row of
the display. Only digital I/O input channels are dis-
played.
Model 7002 mainframe — The real-time state (on or
off) of each input channel is provided on the first row of
the appropriate LED display grid. Use the TYPE option
of the CARD CONFIG MENU if you do not know
which slot the card is installed in.
3. Use the EXIT key to exit from the “read input channels”
display mode.
NOTE
With input channels displayed, you can
turn off (open) all other channels by press-
ing OPEN ALL.
IEEE-488 bus operation
Bus operation is demonstrated using Microsoft QuickBASIC
4.5, the Keithley KPC-488.2 (or Capital Equipment Corpo-
ration) IEEE interface and the HP-style Universal Language
Driver (CECHP). Refer to “QuickBASIC 4.5 Programming”
in the mainframe manual for details on installing the Univer-
sal Language Driver, opening driver files, and setting the
input terminal. Program statements assume that the primary
address of the mainframe is 07.
Closing and opening channels
The following SCPI commands are used to open and close
relay and digital I/O output channels:
:CLOSe <list>
Closes specified channels
:OPEN <list>|ALL
Opens specified (or all) channels.
The following program statement turns on channels 1!1, 1!4
through 1!6, and the channels that make up channel pattern
M1.
PRINT #1, "output 07; clos (@ 1!1, 1!4:1!6, M1)"
Notice that the colon (:) is used to separate the range limits.
Either of the following statements turns off channels 1!1, 1!4
through 1!6, and the channels of M1:
PRINT #1, "output 07; open (@ 1!1, 1!4:1!6, M1)"
PRINT #1, "output 07; open all"
Scanning output channels
There are many commands associated with scanning. How-
ever, it is possible to configure a scan using as little as four
commands. These commands are listed as follows:
*RST
:TRIGger:COUNt:AUTo ON
:ROUTe:SCAN <list>
:INIT
The first command resets the mainframe to a default scan
configuration. The second command automatically sets the
channel count to the number of channels in the scan list, the
third command defines the scan list, and the fourth command
takes the Model 7001/7002 out of the idle state.
The following program fragment will perform a single scan
of channels 1 through 4 of slot 1 and the channels that make
up channel pattern M1:
PRINT #1, "output 07; *rst"
PRINT #1, "output 07; trig:coun:auto on"
PRINT #1, "output 07; scan (@ 1!1:1!4, M1)"
PRINT #1, "output 07; init"