1766-RM001A-EN-P MicroLogix 1400 Programmable Controllers ...

Chapter 22Communications InstructionsThis chapter contains information about the Message (MSG) and ServiceCommunications (SVC) communication instructions. This chapter providesinformation on:• Messaging Overview on page 393• SVC - Service Communications on page 396• MSG - Message on page 398• The Message Element on page 399• Timing Diagram for the MSG Instruction on page 407• MSG Instruction Ladder Logic on page 411• Local Messages on page 413• Configuring a Local Message on page 414• Local Messaging Examples on page 423• Remote Messages on page 439• Configuring a Remote Message on page 442• Configuring a Multi-hop Remote Message on EtherNet/IPCommunication Channel on page 445• Configuring a MicroLogix 1400 CIP Generic Message via Ethernet onpage 461• MSG Instruction Error Codes on page 466• Special Function with MSG instruction on page 468The communication instructions read or write data to another station.Instruction Used To: PageSVC Interrupt the program scan to execute the service communicationspart of the operating cycle. The scan then resumes at the instructionfollowing the SVC instruction.396MSG Transfer data from one device to another. 398Messaging OverviewThe communication architecture is comprised of three primarycomponents:• Ladder Scan• Communications Buffers393 Publication 1766-RM001A-EN-P - October 2008