/** Handles initialization, output and polling from within the running thread */
protected synchronized AbstractMRMessage pollMessage() {
// ensure validity of call
if (getNumNodes() <= 0) {
return null;
}
// move to a new node
curSerialNodeIndex++;
if (curSerialNodeIndex >= getNumNodes()) {
curSerialNodeIndex = 0;
}
// ensure that each node is initialized
if (getMustInit(curSerialNodeIndex)) {
setMustInit(curSerialNodeIndex, false);
AbstractMRMessage m = getNode(curSerialNodeIndex).createInitPacket();
if (m != null) { // SECSI boards don't need this yet
log.debug("send init message: " + m);
m.setTimeout(2000); // wait for init to finish (milliseconds)
return m;
} // else fall through to continue
}
// send Output packet if needed
if (getNode(curSerialNodeIndex).mustSend()) {
log.debug("request write command to send");
AbstractMRMessage m = getNode(curSerialNodeIndex).createOutPacket();
getNode(curSerialNodeIndex).resetMustSend();
m.setTimeout(500);
return m;
}
// poll for Sensor input
if (getNode(curSerialNodeIndex).getSensorsActive()) {
// Some sensors are active for this node, issue poll
SerialMessage m = SerialMessage.getPoll(getNode(curSerialNodeIndex).getNodeAddress());
if (curSerialNodeIndex >= getNumNodes()) {
curSerialNodeIndex = 0;
}
return m;
} else {
// no Sensors (inputs) are active for this node
return null;
}
}
