GE VersaMax PLC - Page 13

12 Serial I/O / SNP / RTU Protocols .............................................................................................225
12.1 Format of the Communication Request Function.........................................................................................226
12.1.1 Parameters of the COMMREQ Function.............................................................................................226
12.1.2 Command Block for the COMMREQ Function....................................................................................227
12.1.3 Example of the COMMREQ Function................................................................................................227
12.2 Configuring Serial Ports Using the COMMREQ Function ............................................................................228
12.2.1 Timing .........................................................................................................................................228
12.2.2 Sending Another COMMREQ to the Same Port ...................................................................................228
12.2.3 Invalid Port Configuration Combinations............................................................................................229
12.2.4 RTU Slave/SNP Slave Operation With Programmer Attached.................................................................229
12.2.5 Example COMMREQ Command Block for Configuring SNP Protocol ....................................................230
12.2.6 Example COMMREQ Data Block for Configuring RTU Protocol ...........................................................231
12.2.7 Example COMMREQ Data Block for Configuring Serial I/O Protocol .....................................................232
12.3 Calling Serial I/O COMMREQs from the PLC Sweep .................................................................................233
12.3.1 Compatibility ................................................................................................................................233
12.3.2 Status Word for Serial I/O COMMREQs ............................................................................................233
12.4 Serial I/O COMMREQ Commands ..........................................................................................................236
12.4.1 Overlapping COMMREQs...............................................................................................................236
12.4.2 ...................................................................................................................................................236
12.4.3 COMMREQs that Can be Pending While Others Execute ......................................................................237
12.4.4 Initialize Port Function (4300) ..........................................................................................................237
12.4.5 Set Up Input Buffer Function (4301)..................................................................................................238
12.4.6 Flush Input Buffer Function (4302) ...................................................................................................238
12.4.7 Read Port Status Function (4303) ......................................................................................................239
12.4.8 Write Port Control Function (4304) ...................................................................................................242
12.4.9 Cancel Commreq Function (4399).....................................................................................................243
12.4.10Autodial Function (4400) ................................................................................................................243
12.4.11Write Bytes Function (4401) ............................................................................................................245
12.4.12Read Bytes Function (4402).............................................................................................................246
12.4.13Read String Function (4403) ...........................................................................................................247
13 Ethernet Communications .......................................................................................................249
13.1 Overview of the Ethernet Interface ...........................................................................................................250
13.1.1 Ethernet Global Data ......................................................................................................................250
13.1.2 SRTP Server .................................................................................................................................251
13.1.3 SRTP Channels..............................................................................................................................251
13.1.4 Attachment to the Ethernet LAN .......................................................................................................251
13.1.5 The Station Manager Software..........................................................................................................251
13.2 IP Addressing.......................................................................................................................................252
13.3 Routers ...............................................................................................................................................253
13.4 Ethernet Global Data .............................................................................................................................254
13.4.1 The Frequency of Sending/Receiving an Exchange...............................................................................254
13.4.2 The Consumer Update Timeout Period ...............................................................................................254
13.4.3 Ethernet Global Data Groups............................................................................................................255
13.4.4 Timestamping of Ethernet Global Data Exchanges ...............................................................................255
13.4.5 Configuring NTP for the CPUE05 Ethernet Interface ............................................................................257
13.4.6 The Content of an Ethernet Global Data Exchange ...............................................................................258
GFK-1503E User Manual 13
For public disclosure