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DPU Bus

Troubleshooting

277581 Rev. A1

Summary of Contents for DPU Bus

Page 1: ...DPU Bus Troubleshooting 277581 Rev A1 ...

Page 2: ...MAX Controls equipment Your comments and suggestions are welcome Metso Automation MAX Controls 1180 Church Road Lansdale PA 19446 Attention Manager Technical Publications Warning Do not look into the end of an optical cable EYE DAMAGE CAN RESULT Copyright 1999 2001 by Metso Automation MAX Controls Inc Printed in the United States of America All Rights Reserved ...

Page 3: ...allout 1 11 Go Ahead Pointers and Station Addresses 1 12 IGAP and UGAP Procedures 1 12 Performing an IGAP 1 13 Performing a UGAP unigap 1 13 CHAPTER 2 2 1 Verifying DPU Bus Performance 2 1 Overview 2 1 Ideal Verification Conditions 2 1 Verification Procedure Overview 2 2 Beginning Verification Procedure 2 2 DPU Bus Maintenance 2 4 CHAPTER 3 3 1 Using maxVUE Runtime Troubleshooting Displays 3 1 Ove...

Page 4: ...DPU Bus Troubleshooting Metso Automation MAX Controls 277581 CHAPTER 4 4 1 Troubleshooting Tips and Pointers 4 1 Troubleshooting Prerequisites 4 1 Troubleshooting Pointers and Reminders 4 2 ...

Page 5: ...essible from the maxSTATION To verify DPU Bus operation after you logically configure a DPU Bus and to troubleshoot the DPU Bus you will view standard system status displays accessible via maxVUE Runtime which runs as a Windows NT package on the maxSTATION Refer to Chapter 3 for a discussion of these displays Chapter 1 contains general information about the architecture station addressing and timi...

Page 6: ...ters to extend optical cable lengths beyond 6 600 feet nominally 2 km See Understanding OEIs All components exist in pairs providing clockwise CW and counterclockwise CCW data paths The DPU Bus design uses two totally redundant paths for communication If one path fails the other will handle all communication tasks with no loss of communication or DPU Bus performance All messages traverse both the ...

Page 7: ... DBM 2 DPU DPU OEI s 1 Pair per electrical spur T T T T T T Maximum length of electrical spur 200 feet from OEI to Terminator 15 stations maximum per electrical spur DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU DPU Figure 1 1 Optical DPU Bus Architecture ...

Page 8: ...a system consisting of two redundant optical repeater rings may be used See next section Figure 1 2 DPU Bus Special Cases Three DPU Bus Networking Approaches The DPU Bus can be implemented in three ways a fiber optic ring with redundant electrical spurs a Wrap back OEI network or an Electrical only network DBM 1 DBM 2 T T DPU DPU DPU DPU DPU Electrical Only Network DPU T T Female terminators repla...

Page 9: ...twork approach See Figure 1 2 A wrap back OEI network uses only one pair of OEIs A short length of optical cable connects the OEI optical emitter to the optical detector as shown in Figure 1 2 See Figure 1 3 for a depiction of an OEI Electrical cable is used to connect DPUs and DBMs The electrical cable portion is treated as a electrical spur As such the electrical cable may extend up to 200 feet ...

Page 10: ...al data to the fiber optic cable optical data leaves the optical OEI emitter Ring data from the fiber optic cable at the OEI ring data is received by the optical detector of the OEI Bidirectional electrical data between the OEI and modems of stations on the local electrical spur An OEI functions either as a repeater or as a transmitter when it is connected to an electrical DPU Bus When no stations...

Page 11: ...h for Model OEI022 OEI Optical Cable Length for Model OEI012 OEI Retain Jumper Greater than 3900 ft 1 2 km Greater than 3300 ft 1 0 km Remove Jumper Less than 3900 ft 1 2 km Less than 3300 ft 1 0 km No longer supplied for new installations Figure 1 3 Optical Electrical Interface with Terminations ...

Page 12: ...DPU Bus Basics an Introduction Metso Automation MAX Controls 277581 1 7 Figure 1 4 Local Station Not Transmitting Figure 1 5 Local Station Transmitting ...

Page 13: ...ect Interface HDI Model 586 Historical Data Processor HDP Controllers Model 552 Controller File and earlier models System Monitor Functionality DPU Bus Modules DBM view all traffic on the entire DPU Bus network DBMs can obtain DPU Bus performance and status information and detect faults System monitors can initialize a DPU Bus when stations are added or deleted and can restart the token passing pr...

Page 14: ...een the two loops In systems where there are only a few DPUs load balancing is not usually a problem However the system can be made to operate more efficiently by balancing the traffic load between the two low loops Controller Files and DPUs should be evenly distributed between low loop A addresses 32 through 47 and low loop B addresses 48 through 63 if possible These devices cannot perform DPU Bu...

Page 15: ...ny reference to that station address would indicate the same DBM Token Passing and DPU Bus Mastership A maxDNA DPU Bus network uses token passing topology The token is defined as a virtual symbol of the right to initiate communications on the DPU Bus Token passing is the rotation of mastership among stations on a DPU Bus Mastership is defined as possession of the token The token passing procedure ...

Page 16: ...other low loop Note that token passing involves a station number address not the physical location of a station No two stations may have the same address on a given DPU Bus Token passing proceeds from station to station without any intervention However the token is monitored by the system monitors to ensure proper operation and to report and correct any malfunctions Stallout A stallout is defined ...

Page 17: ...the Initialize Go Ahead Pointers IGAP command to optimize token rotation as described in the IGAP procedure below In addition to these pointers system monitors maintain other pointers to the two low loops These pointers represent the first active station and the first station in each loop corresponding to the next address and permanent next address above IGAP and UGAP Procedures A procedure known ...

Page 18: ...able DBM Status Display objects Each object shows the current condition of the maxNET redundant Ethernet network and DPU Buses of each subsystem Select an object for a desired DBM and click the Map button inside the object to access the DPU Bus Map display either Bus 1 or Bus 2 if present 3 With this display on the screen select the IGAP button at the top of the display The highway is now IGAP d P...

Page 19: ...er The map should indicate hardware locations terminations etc on the DPU Bus s This paper map helps you better understand your system resource requirements Refer to Figure 1 1 and 1 2 for a sample system map Define the DPU Bus and the stations assigned to the DPU Bus using maxTOOLS observing the station count limitations listed in Table 1 1 Lastly verify that the DPU Bus stations are performing c...

Page 20: ...ready in operation or verifying an operating DPU Bus it may be more practical to use your established configuration A DPU Bus and the system resources assigned to the DPU Bus should be defined Perform a full install When you successfully install the blank configuration you may then view it from a maxSTATION running maxVUE Runtime Beginning Verification Procedure During a DPU Bus test you will veri...

Page 21: ...axSTATION Operator s Guide 7 Let the system run for 12 to 24 hours Do not acknowledge any alarms that occur during this trial period 8 After the verification period call up the DPU Bus Map display and print the display again Compare the before printout from step 5 with the after printout from this step With the exception of the token passing rate indicated in the upper right comer of the display t...

Page 22: ...ition Effects on Results Non blank DPU and operating conditions displays Retries and status broadcasts may be greater than 0 Non IGAP d network Retries will be greater than 0 Process or System Alarms Status broadcasts will be indicated from stations reporting alarms DPU Bus Maintenance Routine maintenance is not required for a DPU Bus However the verification procedure should be performed every on...

Page 23: ...TION Operator s Guide Using the System Status Display Access the System Status display to confirm that your DPU Bus network and the associated maxNET network have no cable breaks Figure 3 1 DBM Status Display object To access this display At the maxSTATION bring up maxVUE Runtime and go to the main menu Click the System Status button on the Vertical Toolbar to bring up the System Status display Th...

Page 24: ...us Conditions are complete or broken A red colored loop indicator represents a broken status for that portion of the DPU Bus Token Pass Rate The Token Pass Rate of the DPU Bus appears to the right of the DPU Bus loop indicators This reports the number of times per second the selected DBM device receives the token Using the DPU Bus Map Display From the DBM Status object you may access the DPU Bus M...

Page 25: ...ed If the DPU Bus is IGAP d see below this will be the actual station to which the token is passed PERM Address of the next station to which this station will try to pass the token if the DPU Bus is UGAP d this will usually be this station s address plus one If the DPU Bus is IGAP d this will be the next station that has responded before see NEXT above TYPE Station type types that could be display...

Page 26: ...3 2 DPU Bus Map Display Using IGAP UGAP Buttons etc The display includes buttons labeled IGAP UGAP RZAP and Statistics Refer to the following for a description of their respective functions IGAP The IGAP Initialize Go Ahead Pointers function is used to increase system efficiency by skipping nonexistent station numbers on a DPU Bus Accordingly each time new stations are added in an IGAPed system th...

Page 27: ...r the DPU Bus See Figure 3 5 These are the statistics which are zeroed out by the RZAP button on this display or on the DPU Bus Map display To access this display Access the maxVUE Runtime main menu and click System Status on the Vertical Toolbar to open the System Status display Locate the object for the desired DBM and click the Map button to bring up the DPU Bus Station Status Display See Figur...

Page 28: ...tions in the time allotted for mastership a measure of how busy the DPU Bus and this station are but not errors CRC errors The number of frames received which contained an error detected by the cyclic redundancy check CRC bytes at the end of each frame Stallout recoveries The number of times this station attempted to recover from a stallout Overrun errors The number of times this station s DPU Bus...

Page 29: ...e was being received DCD active The number of times DCD became active while this station was attempting to transmit Total DPU Bus diagnostic alarms The number of remote or diagnostic alarms reported by this DPU Bus processor Clockwise CW Cable Changes Optical cable changes The number of changes in clockwise optical cable status complete to broken or broken to complete Electrical cable changes The ...

Page 30: ...DPU Bus Troubleshooting Metso Automation MAX Controls 277581 3 8 Figure 3 5 DPU Bus Statistic Display ...

Page 31: ...2 which illustrate a sample paper map The map drawn at the time of initial installation should be revised whenever the system is augmented or modified A copy of the DPU Bus Map display Copies of the DPU Bus Statistics displays may also be useful if cable breaks are intermittent or there are other communication alarms For DPU Bus Statistics displays to be useful the following sequence should be fol...

Page 32: ...ue to defective hardware 3 The token is passed in logical numerical sequence regardless of where a station is physically located 4 Messages are broadcast simultaneously on the CW and CCW sides of the DPU Bus the first side to receive the message is used 5 The token is the symbolic right to initiate communications on the DPU Bus It is equivalent to passing the baton in a relay race 6 Cable status i...

Page 33: ...rd location TB1 6 and 7 on an OEI for a given optical cable length refer to the following table to obtain the correct jumper setting for a given length of cable OEI Jumpers Optical Cable Length for Model OEI022 OEI Optical Cable Length for Model OEI012 OEI Retain Jumper Greater than 3900 ft 1 2 km Greater than 3300 ft 1 0 km Remove Jumper Less than 3900 ft 1 2 km Less than 3300 ft 1 0 km No longer...

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