Architecture and hardw are configuration Architecture of the PLC softw are

3.5.7 Architecture and hardw are configuration

Th e co n t ro l syst em is d ivid ed in t o m o d u les acco rd in g t o fu n ct io n al gro u p in gs. Th is ap p lies t o t h e circu it d iagram , t h e arran gem en t o f t h e swit ch cabin et an d st ru ct u re o f t h e PLC so ft ware. Th e fu n ct io n al m o d - u les d o n o t n ecessarily co rresp o n d t o t h e m ech an ical st ru ct u ral u n it s – in so m e cases sim ilar fu n ct io n s su ch as all em ergen cy st o p circu it s, all p ro t ect ive grilles an d t h e lu bricat io n are gro u p ed t o get h er. Criteria u sed to d eterm in e th e con trol stru ctu re in clu d e th e logical an d fu n ction al coh eren ce between d ifferen t system elem en ts an d th e m in i- m ization of in terfaces between th e in d ivid u al grou p s of fu n ction s. A well d esign ed arch itectu re of th e con trol system en h an ces clarity an d tran s- p aren cy of th e electrical d ocu m en tation an d th u s red u ces th e tim e sp en t in d esign an d start-u p as well as in trou blesh oootin g d u rin g p rod u ction .

3.5.8 Architecture of the PLC softw are

Th e PLC so ft ware is d esign ed t o co rresp o n d t o t h e fu n ct io n al gro u p in gs o f t h e circu it d iagram . Fu n ct io n al seq u en ces, in p art icu lar t h o se u sed 101 Press control systems Fig. 3.5.5 PLC European manufacturer Metal Forming Handbook Schuler c Springer-Verlag Berlin Heidelberg 1998 fo r wo rkp iece h an d lin g an d d ie ch an gin g, are p ro gram m ed u sin g seq u en t ial p ro gram m in g m et h o d s. W h ere fast resp o n se t im es are called fo r, t h e relevan t PLC in p u t sign als are d efin ed as in t erru p t in p u t s wh ich , as t h e n am e su ggest s, in t erru p t cyclically p ro cessed co n t ro l so ft - ware fu n ct io n s an d t rigger a resp o n se p ro gram wh ich resp o n d s t o ext er- n al even t s in an ext rem ely sh o rt t im e.

3.5.9 Future outlook