1756-RM001B-EN-P, Using ControlLogix in SIL2 ... - Tuv-fs.com

ControlLogix Communications Modules 5-3Recommendations forCommunications ModulesUseUsers must consider the recommendations listed below when usingSIL2-certified communications modules:• When installing ControlLogix communications modules, followthe information provided in the documentation listed in theRelated Communications Modules Documentation section onpage 5-4.• Use Ethernet for communications to Human-to-MachineInterfaces (HMI) and programming terminals only. For moreinformation on using HMI, see Figure 1.2 on page 1-4 andChapter 10, Use and Application of Human to MachineInterfaces.• Remote I/O chassis should be connected via ControlNet only.• Peer-to-peer communication is restricted to ControlNet only andshould occur only if the controller in the safety loop is sharingits own information (for example, via produced tags) with othercontrollers outside the loop.• For exchanging I/O data, use listen-only connections.• For exchanging non-I/O data, use producer/consumer tags.• Typically, no devices must be permitted to write data to thecontroller in the safety loop. The only exception to thisrecommendation is the use of HMI devices. For moreinformation on how to use HMI in the safety loop,see Chapter 10.For more information on connecting remote I/O chassis andpeer-to-peer communication, see Figure 1.2 on page 1-4.Publication 1756-RM001B-EN-P - October 2003