Winco DGC-2020 - Manual (Page 157)

9400200990 Rev B DGC-2020 Modbus
™ Communication
i
APPENDIX B
• MODBUS™ COMMUNICATION
TABLE OF CONTENTS
INTRODUCTION .......................................................................................................................... B-1
General Overview............................................................................................................ B-1
Intended Use of the Communications Protocol ............................................................... B-1
DETAILED DESCRIPTION OF DGC-2020 MODBUS PROTOCOL............................................ B-1
Modbus Protocol Overview.............................................................................................. B-1
Serial Transmission Details ............................................................................................. B-2
Message Framing / Timing Considerations..................................................................... B-2
Error Handling and Exception Responses ...................................................................... B-2
DETAILED DGC-2020 MESSAGE DEFINITION ......................................................................... B-2
Device Address ............................................................................................................... B-2
Function Code and Data Block........................................................................................ B-2
DATA FORMATS ......................................................................................................................... B-5
Short Integer Data Format (INT8) ................................................................................... B-5
Integer Data Format (INT16) ........................................................................................... B-5
Long Integer Data Format (INT32) .................................................................................. B-6
Floating Point Data Format.............................................................................................. B-6
Double Precision Data Format (DP)................................................................................ B-7
Triple Precision Data Format (TP)................................................................................... B-7
Error Check ..................................................................................................................... B-7
Interdependence of Preset Multiple Register Data ......................................................... B-7
MAPPING - DGC 2020 Parameters into MODICON ADDRESS SPACE .................................... B-8
Table Conventions........................................................................................................... B-8
Legacy Parameter Table ................................................................................................. B-8
Current Parameter Table............................................................................................... B-24