Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 8: Electrical Works  73 of 124  performing all these operations. Operation of modules except faulty module should not be  interrupted during this replacement. 8_Vol3_d4.3_Section 8 electrical works_en_GIR.rev8.doc   CPU will allow to make digital signals 1/0 over program and should support to give  simulation values for analog signals.  CPUs should support 1ms time labeled cards which can be installed over them if necessary.  All CPUs within system should be programmed with same software.  Communication infrastructure between all CPUs and Remote I/O modules will be standard  Ethernet based.   I/Os should be accessed for diagnostic and maintenance purposes over web browser(internet  explorer) over computer which is connected to network. This CPUs should be programmable  such that they can send E-mail.  All explanations regarding with program should be stored in controller CPUs. All data,  variable and remarks should be able to be retrieved from CPUs after connection is made by  computer software.  There will be USB port over controller for making programming easier.  There will be simulation property in controller software program and thereby program can be  tested and controlled even though there is not controller.  Controller will have capacity to process and support minimum 2000 I/Os.  Controller will have capability to increase programming memory of CPU is necessary and will  have minimum 1 MB memory.  Remote I/O terminals will have capacity to support and process 1024 I/Os   . CPUs should have real time clock, Controller module internal clock should be able to be  synchronized with Operator Interface by time synchronization command over NTP server.  Cards to be used in system will have standards and certificates which are mentioned below.  IEC/EN 61131-2   CSA 22.2 N 142   UL 508   ABS, BV, DNV, GL, LR, RINA, RMRS   UL 746C, UL 94   CSA 22.2 No : 213, Class I , Division 2   All cards to be used in system will be able to work at 0.. 600C and will be stored at -25…..+70  $^{0}$C  Controller software will strictly support IEC 61131-3 standard and all of software languages  which are mentioned below will be able to be used.  LD   FBD 