George Giesey wrote:
 
>I have an application "emulating" the old ENQ/ACK protocol linking an
>HP935 to handheld pc's. I am having a problem with the HP "reacting" to a
>DC3 (CTRL-S) character when it received from the handheld. (A DC3 is
>randomly genereated by the handhelp as a CRC value!!! -so I cannot
>control this!!).
>
>I have a supsicion that there is a way to configure a DTC asynch port to
>be "transparent" to ALL control characters!??? Anyone know how to
>accomplish this!!!!
 
and Joe Howell replied:
 
>I assume you have an application running on the 935 which is opening
>the port to communicate with the HH PC's .. (what brand/type?).  If
>that is the case, you might try fopen on the port, then use fcontrol
>to set port behavior to switch to transparent mode.
>
>Sorry I don't have specifics.
>
>The definitive source for answers to questions of this type would be
>Ross Scroggs and the folks at Telemon.  They always seem to give the
                               ^^^^^^^  Sigh.  TelAmon.
>correct answer the first time!
 
Transparent mode [FCONTROL(FILE'NUM,41,non_zero_value)] won't do the
trick alone.  You'll also need to use FDEVICECONTROL to turn off the
DTC's participation in XON/XOFF.  In SPL terms, the code would look
like:
 
        FD'PARM:=0;
        FDEVICECONTROL(FILE'NUM,FD'PARM,192,26,3,ERR'NUM);
 
where FILE'NUM, FD'PARM and ERR'NUM are integers (16-bit).
 
------------
Randy Medd  (aka "folks")
Telamon, Inc.