Siemens SIMATIC S7 System Manual page 12

Table of contents
10.3.1.2 Requirements for using Modbus instructions .................................................................... 515
10.3.1.3 Initialization and execution time for Modbus protocol....................................................... 517
10.3.2 Modbus RTU master ......................................................................................................... 517
10.3.2.1 Using the Modbus RTU master instructions....................................................................... 517
10.3.2.2 MBUS_CTRL / MB_CTRL2 instruction (initialize master) ...................................................... 519
10.3.2.3 MBUS_MSG / MB_MSG2 instruction .................................................................................. 520
10.3.2.4 Modbus RTU master execution error codes ....................................................................... 523
10.3.3 Modbus RTU slave............................................................................................................ 525
10.3.3.1 Using the Modbus RTU slave instructions.......................................................................... 525
10.3.3.2 MBUS_INIT instruction (initialize slave) ............................................................................. 526
10.3.3.3 MBUS_SLAVE instruction.................................................................................................. 528
10.3.3.4 Modbus RTU slave execution error codes .......................................................................... 529
10.3.4 Modbus RTU master example program ............................................................................. 529
10.3.5 Modbus RTU advanced user information........................................................................... 531
10.4 Modbus TCP library .......................................................................................................... 533
10.4.1 Modbus TCP library features ............................................................................................. 533
10.4.2 Modbus TCP client ........................................................................................................... 535
10.4.2.1 MBUS_CLIENT instruction................................................................................................. 535
10.4.2.2 Modbus TCP client execution error codes.......................................................................... 538
10.4.3 Modbus TCP server........................................................................................................... 539
10.4.3.1 MBUS_SERVER instruction ................................................................................................ 539
10.4.3.2 Modbus TCP server execution error codes......................................................................... 540
10.4.4 Example: Modbus TCP application .................................................................................... 541
10.4.5 Modbus TCP advanced user information ........................................................................... 546
10.4.6 Modbus TCP general exception codes ............................................................................... 548
10.4.7 Modbus TCP general communication exception codes ...................................................... 549
10.5 Open user communication library .................................................................................... 550
10.5.1 Parameters common to the OUC library instructions ......................................................... 551
10.5.2 Open user communication library instructions.................................................................. 553
10.5.2.1 TCP_CONNECT instruction ................................................................................................ 553
10.5.2.2 ISO_CONNECT instruction ................................................................................................ 556
10.5.2.3 UDP_CONNECT instruction ............................................................................................... 559
10.5.2.4 TCP_SEND instruction....................................................................................................... 561
10.5.2.5 TCP_RECV instruction ....................................................................................................... 563
10.5.2.6 UDP_SEND instruction...................................................................................................... 566
10.5.2.7 UDP_RECV instruction ...................................................................................................... 569
10.5.2.8 DISCONNECT instruction .................................................................................................. 571
10.5.3 Open user communication library instruction error codes ................................................. 573
10.5.4 Open user communication library example....................................................................... 574
10.5.4.1 Active partner (client) ...................................................................................................... 574
10.5.4.2 CheckErrors subroutine .................................................................................................... 583
10.5.4.3 Active partner symbol table.............................................................................................. 584
10.5.4.4 Passive partner (server).................................................................................................... 585
10.5.4.5 CheckErrors subroutine .................................................................................................... 592
10.5.4.6 Passive partner symbol table ............................................................................................ 592
10.6 PN Read Write Record library ............................................................................................ 592
10.6.1 PN Read Write Record features.......................................................................................... 592
10.6.2 Input and output interface of PN Read Write Record library ............................................... 593
10.6.3 Definition of parameters for input signal "STATUS" ............................................................ 594
10.6.4 System_defined error code of the library PN Read Write Record ......................................... 594
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System Manual, V2.7, 08/2022, A5E03822230-AK
S7-200 SMART