Reference Manual

PMAC 2 Software Reference
PMAC I-Variable Specification 45
The host computer can use the <CONTROL-X> character to clear out PMAC’s
communications buffers and make sure that no unintended responses are received for the
next command. However, without an acknowledgement that the buffers have been
cleared, the host computer has to add a safe delay to ensure that the operation has been
done before the next command can be issued.
Setting I63 to 1 permits a more efficient clearing of the buffer, because the response
character lets the host computer know when the next command can safely be sent.
Versions of the PCOMM32 communications library 2.21 and higher (March 1999 and
newer) can take advantage of this feature for more efficient communications. I63 should
be set to 0 when using older versions of PCOMM32.
In battery-backed PMAC(1) boards with firmware versions 1.16F and 1.16G, the value of
I63 is maintained by the battery through a power cycling or reset; a SAVE command is not
required. In 1.16H and newer (and in all revisions on flash-backed boards), the value is
maintained by storing it to non-volatile memory with a SAVE command.
I64 Internal Response Tag Enable
Range
0 .. 1
Units
None
Default
0
Remarks
I64 permits PMAC to tag ASCII text lines that it sends to the host computer as a result of
internal commands, so these can easily be distinguished from responses to host commands.
If I64 is set to 1, a line of text sent to the host computer as a result of an internal SEND or
CMD statement is preceded by a <CONTROL-B> (“start-transmission”) character. In the
case of an error report, the <CONTROL-B> character replaces the leading <CONTROL-G>
(“bell”) character. The text line is always terminated by a <CR> (carriage return)
character, regardless of the setting of I62.
If I64 is set to 0, a text line sent in response to an internal PMAC command is not preceded
by any special character. Reported errors are preceded by the <CONTROL-G> (“bell”)
character. This is equivalent to the action of older versions of PMAC firmware, before I64
was implemented.
Regardless of the setting of I64, if I6 = 2, errors on internal commands are not reported to
the host computer.
In battery-backed PMAC(1) boards with firmware versions 1.16F and 1.16G, the value of
I64 is maintained by the battery through a power cycling or reset; a SAVE command is not
required. In 1.16H and newer (and in all revisions on flash-backed boards , the value is
maintained by storing it to non-volatile memory with a SAVE command.
Example
With I64=0, lines sent from PMAC are:
Motion Stopped on Limit<CR>
<BELL>ERR003<CR>
With I64=1, the same lines from PMAC are:
<CTRL-B>Motion Stopped on Limit<CR>
<CTRL-B>ERR003<CR>