Failures that do not allow a quick elim­i­na­tion due to their com­plex­i­ty can also occur at exist­ing plants in the course of time. This can be spo­radic occur­ring fail­ures or fail­ures that are dif­fi­cult to detect due to their speed or dura­tion of pres­ence. The nec­es­sary mea­sur­ing equip­ment for this pur­pose will not be held avail­able per­ma­nent­ly in most com­pa­nies due to the small chance of occurrence.

By using the nec­es­sary mea­sur­ing equip­ment Quality Automation GmbH can find a rem­e­dy here in case of dif­fer­ent kinds of fail­ures as:

  • Process flow failures
  • Structural actions in case of hard­ware failures
  • Communication fail­ures – Profibus diagnosis

Process flow failures

A trou­ble-shoot­ing in case of worn out bear­ings, heat devel­op­ment caused by fric­tion or oth­er sources of defects that only occur dur­ing run-time often turns out to be dif­fi­cult by using tra­di­tion­al meth­ods. In order to offer a reli­able fault local­iza­tion the com­pa­ny Quality Automation GmbH has dif­fer­ent record­ing equip­ment at its disposal.

By way of exam­ple it is pos­si­ble to exam­ine exact­ly fast sequences in slow motion by means of high speed-imag­ing or to detect heat absorp­tion at dif­fer­ent places by using ther­mal imag­ing in order to draw con­clu­sions regard­ing sources of defects.

Next to record­ing equip­ment appro­pri­ate record­ing soft­ware offers assis­tance to record tem­po­ral cir­cuit sequences of the SPS dur­ing run-time and to detect pos­si­ble fail­ures in the cours­es of signals.

Communication failures – Profibus diagnosis

A con­tin­u­ous super­vi­sion of the net makes an ear­ly detec­tion of hid­den fail­ures of dif­fer­ent kinds pos­si­ble – in fact before com­mu­ni­ca­tion drops out com­plete­ly. The qual­i­ty of bus sys­tems depends on a vari­ety of fac­tors. Just spo­radic occur­ring bus inter­fer­ences or a com­plete bus drop are often reduced to dam­aged plug sock­ets, par­tic­i­pants or EMV inter­fer­ences. In addi­tion mod­i­fi­ca­tions of plants and com­bined with bus enlarge­ments or short­en­ings can lead to sources of defects in case of not adjust­ed bus parameter.

For local­iza­tion and fail­ure diag­no­sis nec­es­sary equip­ment espe­cial­ly for phys­i­cal mea­sure­ment is in need. Quality Automation GmbH pos­sess­es mea­sur­ing equip­ment that enables an analy­sis, super­vi­sion, trou­ble-shoot­ing and main­te­nance of PROFIBUS-systems.

Typical inter­fer­ences dur­ing the oper­a­tion of PROFIBUS-plants like loss of par­tic­i­pant, com­mu­ni­ca­tion fail­ures, “over­shoot­er” or even down­time of the plant are often caused by bus electrics und cabling. The sig­nal con­di­tions that help to detect and to elim­i­nate fail­ure caus­es quick­ly are pre­sent­ed clear­ly on the bus. Besides the through­put can also be improved by a tar­get­ed Profibus diagnosis.

Just before the accep­tance of a new plant it is rea­son­able to per­form a Profibus diag­no­sis as pre­ven­tive fail­ure avoid­ance in order to pre­vent a drop down in after­wards operation.

In the fol­low­ing it makes sense to check the bus qual­i­ty at reg­u­lar inter­vals in order to coun­ter­act a wors­en­ing of the bus physics in time and to avoid pro­duc­tion downtimes.