Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 154)

II. SOFTWARE GUIDES - 9. Driver488/SUB 9B. Installation & Configuration
Personal488 User’s Manual, Rev. 3.0 II-139
•
Counter/Timer: This field is the base address of the Counter/Timer registers. It is only
applicable for MP488CT boards. Note the Counter/Timer SCPI communication parameters are
configured as an external device. Refer to the Hardware Guides and section for more information.
•
Bus Terminators: The IEEE 488 bus terminators specify the characters and/or end-or-identify
(
EOI ) signal that is to be appended to data that is sent to the external device, or mark the end of
data that is received from the external device.
This second Driver488/SUB
configuration example displays
an IEEE interface with the
NB488 interface module
specified. This screen
resembles the previous IEEE
interface example with the
exception of 3 different
configuration parameters which
are described below.
Configuration Parameters
•
LPT Port: The LPT port
is the external parallel port
to be connected to the
NB488. Valid selections
are:
LPT1 , LPT2 or LPT3 .
This field takes the place
of the I/O Address field.
•
Enable Printer Port:
Because most laptop and notebook PCs provide only one LPT port, the NB488 offers LPT pass-
through for simultaneous IEEE 488 instrument control and printer operation. If this option is
selected, a printer connected to the NB488 will operate as if it were connected directly to the LPT
port. If not enabled, then the printer will not operate when the NB488 is active. The disadvantage
of pass-through printer support is that it makes communications with the NB488 about 20%
slower.
•
LPT Port Type: This field is used to specify whether the LPT port is a standard IBM
PC/XT/AT/PS/2 compatible port. Valid options are: Standard or 4-bit. The slower 4-bit option is
provided for those computers which do not fully implement the IBM standard printer port. These
computers can only read 4 bits at a time from the NB488 making communication with the NB488
up to 30% slower.
A test program has been provided with NB488 to help identify the user’s LPT port type. Once the
NB488 is installed, type:
NBTEST.EXE . This program will determine if your computer can
communicate with the NB488 and what type of LPT port is installed (Standard or 4-bit).
It is important to note there are four different versions of the NB488 driver. The CONFIG utility
determines which is to be used based on the user-defined parameters. If both pass-through printer
support and the 4-bit LPT port support are selected, then the communication with the IEEE 488 bit
may be slowed as much as 40% compared with the fastest case in which neither option is selected.
The actual performance will vary depending on the exact type and speed of the computer used.
To save your changes to disk, press , or to exit without making any changes, press . All
changes will be saved in the directory where you installed Driver488/SUB. If at any time you wish to
alter your Driver488/SUB configuration, simply rerun
CONFIG .