ControlMaster CM10, CM15, CM30, CM50, CMF160 and CMF310
Universal process controllers and indicator,
1
/8,
1
/4,
1
/2 DIN and fieldmount Contents
IM/CM/C–EN Rev. H 1
Contents
1 Safety .......................................................................... 3
1.1 Electrical Safety ................................................... 3
1.2 Symbols .............................................................. 3
1.3 Health & Safety .................................................... 4
2 Introduction ................................................................ 5
2.1 EC Directive 89/336/EEC ..................................... 5
3 Communication Overview .......................................... 6
3.1 Communication Options ...................................... 6
3.1.1 Ethernet .................................................. 6
3.1.2 RS 485 MODBUS ................................... 7
4 Communication Level ................................................ 8
4.1 Communication ................................................... 8
5 MODBUS Communications ..................................... 13
5.1 Electrical Connections ....................................... 13
5.2 Host Computer Serial Communications ............. 13
5.3 Two-wire and Four-wire Connection .................. 16
5.4 Pull-up and Pull-down Resistors ........................ 17
5.5 Termination Resistor .......................................... 17
5.6 Serial Connections ............................................. 18
6 MODBUS Tables ....................................................... 19
6.1 Input Coils – Digital Inputs (MODBUS Function
Code 02 [Read Input Status]) ............................. 19
6.2 Input Coils – Profile Registers (MODBUS
Function Code 02 [Read Input Status]) ............... 21
6.3 Write Only Coils
(MODBUS Function Code 05 [Force Single Coil]) 21
6.4 Output Coils (MODBUS Function Code 01 [Read
Coil Status] or 05 [Force Single Coil]) .................. 22
6.5 Input Registers (MODBUS Function Code 04
[Read Input Register]) ......................................... 22
6.5.1 Read-only 32 Bits ................................. 22
6.5.2 Read-only Single Precision Float
(MODBUS Function Code 04
[Read Input Register]) ............................ 22
6.5.3 Input Registers For Bytes
(MODBUS Function Code 04
[Read Input Registers]) .......................... 24