Watlow CLS200, MLS300 and CAS200 - Manual (Page 3)

Contents
Communications Specification i
Contents
Overview........................................................................ 1
In This Manual ............................................................ 1
Chapter 1: ANAFAZE/AB Protocol............................. 3
Protocol Syntax .................................................................3
Control Codes.............................................................. 3
Transaction Sequence.................................................. 4
Packet Format.............................................................. 6
Codes in a Packet ........................................................ 6
Error Checking ..................................................................8
Block Check Character (BCC) .................................... 8
Cyclic Redundancy Check (CRC)............................... 9
Examples ...........................................................................10
Block Read .................................................................. 10
Block Write ................................................................. 13
Message Data ....................................................................14
Data for a Read Command .......................................... 14
Data for a Write Command ......................................... 15
Two-Byte Data Types ................................................. 15
Figuring Block Size..................................................... 15
Anafaze/AB Data Table Summary ....................................16
Ordering of Heat and Cool Channel Parameters ......... 17
Ordering of Ramp-Soak Profile Parameters................ 17
Anafaze/AB Protocol Data Table................................ 17
Chapter 2: Modbus-RTU Protocol............................... 21
Overview ...........................................................................21
Transactions on Modbus-RTU Networks ................... 21
The Query-Response Cycle......................................... 22
Serial Transmission ..................................................... 22
Message Framing ........................................................ 23
CRC Error Checking ................................................... 25
Function Codes............................................................ 26
Writing Data ................................................................ 30
Reading Data ............................................................... 30
Examples ...........................................................................31
Read Examples ............................................................ 31
Write Examples ........................................................... 32
Modbus-RTU Data Table Summary ..................................33
Ordering of Heat and Cool Channel Parameters ......... 34
Ordering of Ramp-Soak Profile Parameters................ 34
Relative and Absolute Modbus Addresses.................. 35
Modbus-RTU Protocol Data Table ............................. 35