IOtech Digital488, Manual

Page: 24 / 64

Data Dn....Z
The Data command outputs up to 40 bits of data to the output ports. The number of bits, which can be sent
with the Data command, is limited by the number of bits programmed as outputs. For formats
F0 through F3 , if the amount of data sent is less than the number of bits programmed as outputs,
the least-significant bits will contain the data sent and the most-significant bits will be cleared to logic zero.
If a single port is selected with the
Port command, only eight bits may sent with the Data command.
The Data Strobe output is pulse for approximately 50 microseconds after new data is output on the
selected ports.
For formats F0 through F3 , data sent by the controller is contained within a prefix ( D ) and a suffix ( Z ).
In format F4 , the five bytes immediately following the prefix ( D ) is interpreted as data and the suffix ( Z )
is not used. For the high-speed binary F5 format, all bytes received are treated as data and the prefix and
suffix are not used. Refer to the Fn command for additional details.
Dn...Z n... represents the data to be outputted, terminated by Z .
In the F4 mode, the Z terminator is not allowed
Example:
CLEAR 718
reset the Digital488
OUTPUT 718;"C5P1X" all ports as output, select port 1
OUTPUT 718;"D55ZX" send 55 to port 1
ENTER 718; A$ read data from port 1
DISP A$
display shows 55
OUTPUT 718;"P0X" select all ports
OUTPUT
718;"D1234567890ZX" send data to all 40 bits
ENTER 718;A$ read data from the Digital488
DISP A$
display shows 1234567890
OUTPUT 718;"D123ZX" send 12 bits of data to the least significant bits
ENTER 718; A$ read data from the Digital488
DISP A$
display shows 0000000123
OUTPUT
718;"P5D21ZX" set port 5 only
OUTPUT 718;"P0X" select all ports
ENTER 718; A$ read data from the Digital488
DISP A$
display shows 2100000123
Digital488 User’s Manual
7-17-01
Command Descriptions, 3-3