4635 LPS ADDITIONAL MESSAGESMessages 544 through 574Messages 544 through 574 are the result ofproblems/warnings/status that could occur during the processingof messages and signals/interrupts from the system controller(ESS) or during the sending of commands to the systemcontroller.544 Signal expected but not receivedThe PC user interface was expecting to receive signal data.Action Select the OK header button to retry the process. If the problempersists, call Xerox Customer Service.545 Protocol ErrorAn incomplete or damaged protocol packet was received.Action Select the OK header button to retry the process. If the problempersists, call Xerox Customer Service.546 Queue has no entriesPC user interface integrity problem. It has received a signal, butthe data was not found in the queue.Action Select the OK header button to retry the process. If the problempersists, call Xerox Customer Service.547 Second NAK detectedTwo consecutive attempts to send a packet of data to the systemcontroller have failed. The transmission is lost.Action Select the OK header button to retry the process. If the problempersists, call Xerox Customer Service.550 Can’t get communications stateThe call to GetCommState failed.Action 1. Ensure no other Microsoft Windows applications using thecommunication ports are running.2. Select the OK header button to retry the process. If theproblem persists, call Xerox Customer Service.551 Can’t open communications deviceThe requested communications port was unavailable.Action 1. Ensure no other Microsoft Windows applications using thecommunication ports are running.2. Ensure COM port is properly configured.3. Select the OK header button to retry the process. If theproblem persists, call Xerox Customer Service.XEROX 4635 LASER PRINTING SYSTEM MESSAGE GUIDE 15-3