Looks like the post needs to be modified to accept a zero spindle speed.
The Haas post with probing looks like this to negate the spindle RPM issue:
if (!isProbeOperation() &&
(insertToolCall ||
forceSpindleSpeed ||
isFirstSection() ||
(rpmFormat.areDifferent(tool.spindleRPM, sOutput.getCurrent())) ||
(tool.clockwise != getPreviousSection().getTool().clockwise))) {
forceSpindleSpeed = false;
if (tool.spindleRPM < 1) {
error(localize("Spindle speed out of range."));
return;
}
if (tool.spindleRPM > 12000) {
warning(localize("Spindle speed exceeds maximum value."));
}
writeBlock(
sOutput.format(tool.spindleRPM), mFormat.format(tool.clockwise ? 3 : 4)
);
}
and this is the generic Hurco post for the same section:
if (insertToolCall ||
forceSpindleSpeed ||
isFirstSection() ||
(rpmFormat.areDifferent(tool.spindleRPM, sOutput.getCurrent())) ||
(tool.clockwise != getPreviousSection().getTool().clockwise)) {
forceSpindleSpeed = false;
if (tool.spindleRPM < 1) {
error(localize("Spindle speed out of range."));
return;
}
if (tool.spindleRPM > 65535) {
warning(localize("Spindle speed exceeds maximum value."));
}
writeBlock(
sOutput.format(tool.spindleRPM), mFormat.format(tool.clockwise ? 3 : 4)
);
}
You should be able to modify from there, unfortunately I don't have much time to help directly.