AADvance Safety Manual - Tuv-fs.com

AADvance Safety ManualSILSafety Integrity Level. One of four possiblediscrete levels, defined in IEC 61508 and IEC61511, for specifying the safety integrityrequirements of the safety functions to beallocated to a safety-related system. SIL4 hasthe highest level of safety integrity; SIL1 hasthe lowest.The whole of an installation (of which theAADvance system forms a part) must meetthese requirements in order to achieve anoverall SIL rating.SISSafety Instrumented System. A form ofprocess control that performs specifiedfunctions to achieve or maintain a safe stateof a process when unacceptable ordangerous process conditions are detected.SNTPSimple Network Time Protocol. Used forsynchronizing the clocks of computersystems over packet-switched, variablelatencydata networks.structured textA high level IEC 61131-3 language withsyntax similar to Pascal. Used mainly toimplement complex procedures that cannotbe expressed easily with graphical languages.synchronousA data communications term describing aserial transmission protocol. A pre-arrangednumber of bits is expected to be sent acrossa line per second. To synchronise thesending and receiving machines, a clockingsignal is sent by the transmitting computer.There are no start or stop bits.TTASee 'termination assembly'.targetAn attribute of a 'configuration' whichdescribes characteristics of the AADvancecontroller on which the configuration willrun. Includes characteristics such as thememory model and the sizes of variabletypes for the controller.TCPTransmission control protocol. One of thecore protocols of the Internet Protocolsuite. It provides reliable, ordered deliveryof a stream of bytes from a program on onecomputer to another program on anothercomputer. Common applications include theWorld Wide Web, e-mail and file transferand, for an AADvance controller, Modbuscommunications over Ethernet.termination assemblyA printed circuit board which connects fieldwiring to an input or output module. Thecircuit includes fuses for field circuits. Theboard carries screw terminals to connectfield wiring to the controller, and the wholeassembly clips onto the 9300 I/O base unit.TMRTriple modular redundant. A fault tolerantarrangement in which three systems carryout a process and their result is processedby a voting system to produce a singleoutput.TÜV certificationIndependent third party certification againsta defined range of international standardsincluding IEC 61508.UURack unit. A unit of measure used todescribe the height of equipment intendedfor mounting in a standard rack. Equivalentto 44.45mm (1-¾ inches).VvalidationIn quality assurance, confirmation that theproduct does what the user requires.verificationIn quality assurance, confirmation that theproduct conforms to the specifications.7-8 Document number 553630 Issue 7: February 2010