Endress+Hauser Liquiline CM44 series - Default Chapter; Table of Contents

SD01189C/07/EN/04.17
Endress+Hauser
2 © Copyright Dec. 2016
Table of contents
1 Note ............................................................................................................................................................ 4
1.1 About this manual .................................................................................................................................. 4
1.2 Abbreviations .......................................................................................................................................... 4
2 Installation and wiring ............................................................................................................................... 5
2.1 A-, B-wire ................................................................................................................................................ 5
2.2 Termination ............................................................................................................................................ 5
3 Modbus Protocol ........................................................................................................................................ 6
3.1 Specification ............................................................................................................................................ 6
3.2 Basic principle ......................................................................................................................................... 6
3.2.1 General ............................................................................................................................................. 6
3.2.2 Modbus exception codes................................................................................................................. 7
3.3 Transmission Modes .............................................................................................................................. 7
3.3.1 ASCII ................................................................................................................................................. 7
3.3.2 RTU ................................................................................................................................................... 8
3.3.3 TCP ................................................................................................................................................... 8
3.4 Supported Function codes ...................................................................................................................... 9
3.4.1 FC03 Read Holding Register ......................................................................................................... 10
3.4.2 FC04 Read Input Register ............................................................................................................. 10
3.4.3 FC08 Diagnostics (only serial) ...................................................................................................... 11
3.4.4 FC16 Write Multiple Register ....................................................................................................... 12
3.4.5 FC23 Read/Write Multiple Register ............................................................................................. 12
4 Commissioning ......................................................................................................................................... 13
4.1 Modbus RS485 ..................................................................................................................................... 13
4.2 Ethernet ................................................................................................................................................ 14
4.2.1 Verifying the connection ............................................................................................................... 15
4.3 Modbus TCP .......................................................................................................................................... 15
4.4 Byte Order ............................................................................................................................................. 16
4.4.1 Integer (16 Bit).............................................................................................................................. 16
4.4.2 Float / Integer (32 Bit) ................................................................................................................. 16
4.4.3 String .............................................................................................................................................. 16
4.5 Device variables .................................................................................................................................... 17
4.5.1 AI – Analog input (PLCDevice) ................................................................................................. 17
4.5.2 Example ......................................................................................................................................... 18
4.5.3 DI – Digital input (PLCDevice) .................................................................................................. 19
4.5.4 AO – Analog output (PLCDevice) ............................................................................................. 20
4.5.5 DO – Digital output (PLCDevice) .............................................................................................. 20
4.5.5.1 Example: Hold over Modbus ................................................................................................ 21
5 Diagnostics ............................................................................................................................................... 22
5.1 LED displays .......................................................................................................................................... 22
5.2 Status of device variables ..................................................................................................................... 22
5.3 Status signal .......................................................................................................................................... 22
5.4 Diagnostic messages ............................................................................................................................ 23
5.4.1 Device related diagnostics ............................................................................................................ 23
5.4.2 Sensor related diagnostics ............................................................................................................ 24
5.4.2.1 Current diagnostic message ................................................................................................. 24
5.4.2.2 Last active diagnostic message ............................................................................................ 25
5.5 Communication related diagnostics .................................................................................................... 25
5.5.1 Bus termination ............................................................................................................................. 25
5.5.2 Protocol counters........................................................................................................................... 25
6 Applications .............................................................................................................................................. 26
6.1 CA80xx: How to start Measurement, Calibration and Cleaning ....................................................... 26
6.1.1 Activate “Fieldbus”-mode using the device menu ....................................................................... 28