Instruction Manual
10
3.4 DEFINING I/O LINES AS INPUTS OR OUTPUTS (CONTROL MODE ONLY)
If Control Mode is selected the user may define the four groups of I/O lines as input or
output for each group.
XD (abcd) <CR>
D is the Direction indicator a, b, c and d are
either 0 or 1 indicating whether group 1, 2, 3
and 4, respectively, are inputs (0) or outputs
(1).
Example:
Command:
XD0011 <CR>
Sets group 1 and 2 (lines 0-7)as input and
group 3 and 4 (lines 8-15) as outputs.
Response:
XD0011 <CR><LF>
To query the data direction setting for the AEX:
XDQ <CR>
Example:
Command:
XDQ <CR>
Response:
XD0011 <CR><LF>
I/O line group data direction settings are read from EEROM upon power-up and
microprocessor reset.
NOTE:
Hardwire jumpers on the Expander Card itself
MUST
be configured to
match the software setting of inputs and outputs or false data may be read. Jumpers
J4, J5, J6 and J7 are factory-installed to configure the four banks as outputs. The user
must remove (cut) jumpers for any banks he wishes to use as inputs.
3.5 READING INDIVIDUAL I/O LINE STATUS
All I/O lines, whether designated as inputs or outputs, may be queried see their HIGH or
LOW status. All lines must be addressed by their two-digit I/O Line Nr (00-21). If the
line specified is an input, the current input level will be reported. If the line specified is
an output, then the output status will be reported.
XS (n) <CR>
S is the status indicator
n is the line nr. 00 to 21
Example:
Command:
XS03 <CR>
Read I/O line nr 3
Response:
XS03F <CR><LF>
Input 3 is OFF (LOW level TTL signal)