Appendix A: Communication
A.2 Protocol Description
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Examples of MODBUS Master Requests
Here are some examples of read/write operations in a MODBUS Master system.
The syntax is an example and differs between different master systems.
Comli Communication
Comli is a general asynchronous, serial communication protocol, utilizing the
master/slave relationship and communication in only one direction at the time
(Half-duplex).
ECA can only work as a Comli slave and supports the following message types.
Type 0 – transfer of I/O RAM Status or Register value.
Type 1 – acknowledge correctly received data.
Type 2 – request of I/O RAM Status or Register value
Type 3 – transfer of status for one I/O bit.
Type 4 – request of status for one I/O bit.
Message Structure
There are five message types recognised by the controller. Each message type sent
has a given number of characters, or more precisely, a given number of bytes of
02
Illegal data address
03
Illegal data value
Operation
Syntax in Master
Operation in ECA
Read Coil Status
C3
Read I/O RAM Map bit 3
Read Input Status
I1076 or I10076
Read I/O RAM Map bit 76
Read Holding Registers HR4006, HR40006
Read Register Map R6 (AIC6)
Read Input Registers
IR3033, IR30033
Read Register Map R33 (AI1)
Force Single Coil
C208
Write I/O RAM Map bit 208
Preset Single Register
IR3052, HR4052,
IR30052, HR40052
Write Register Map R52
(ISP1)
Code
Name
Summary of Contents for ECA06
Page 1: ...Version 1 05 ECA06 60 600 EMA60 Configuration and Installation ...
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Page 3: ...ECA06 60 600 EMA60 Configuration and Installation ...
Page 10: ...Contents vi 493 0736 11 6 2 ...
Page 16: ...1 5 Version information Chapter 1 Introduction 16 493 0736 11 6 2 ...
Page 200: ...4 2 Annual Check Chapter 4 Maintenance 200 493 0736 11 6 2 ...
Page 286: ...Appendix A Configuration Work Sheets 282 493 0736 11 6 2 ...
Page 304: ...B 1 Total Reset Appendix B Special Modes 298 493 0736 11 6 2 ...
Page 308: ...Index 302 493 0736 11 6 2 ...
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