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Table of Contents
Related Manuals for CARLO GAVAZZI EM21 - COMMUNICATION PROTOCOL V1 REV0
Summary of Contents for CARLO GAVAZZI EM21 - COMMUNICATION PROTOCOL V1 REV0
- Page 1 EM21 COMMUNICATION PROTOCOL Version 1 Revision 0 April 7 , 2008...
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Page 2: Table Of Contents
1.3.1 RS485 general considerations ....................6 1.3.2 MODBUS timing ........................6 TABLES ............................7 Data format representation In Carlo Gavazzi instruments ..............7 2.1.1 Geometric representation ....................7 Maximum and minimum electrical values in EM21 ................7 Instantaneous variables and meters .....................8 Firmware version and revision code .....................8 Programming lock status........................8... -
Page 3: Introduction
Energy management Introduction The RS485 serial interface supports the MODBUS/JBUS (RTU) protocol. In this document only the information necessary to read/write from/to EM21 has been reported (not all the parts of the protocol have been implemented). complete description MODBUS protocol please refer “Modbus_Application_Protocol_V1_1a.pdf”... -
Page 4: Function 04H (Read Input Registers)
Energy management Response frame (incorrect action) Description Length Value Note Physical address 1 byte 1 to F7h (1 to 247) Possible exception : 01h: illegal function Function code 1 byte 02h: illegal data address Exception code 1 byte 01h, 02h, 03h, 04h (see note) 03h: illegal data value 2 bytes 04h: slave device failure... -
Page 5: Function 08H (Diagnostic With Sub-Function Code 00H)
Energy management Response frame (incorrect action) Description Length Value Note Physical address 1 byte 1 to F7h (1 to 247) Possible exception : 01h: illegal function Function code 1 byte 02h: illegal data address Exception code 1 byte 01h, 02h, 03h, 04h 03h: illegal data value 2 bytes 04h: slave device failure... -
Page 6: Application Notes
Energy management Application notes 1.3.1 RS485 general considerations 1. To avoid errors due to the signal reflections or line coupling, it is necessary to terminate the bus at the beginning and at the end (inserting a 120 ohm 1/2W 5% resistor between line B and A in the last instrument and in the Host interface). -
Page 7: Tables
Energy management 2 TABLES Data format representation In Carlo Gavazzi instruments The variables are represented by integers or floating numbers, with 2’s complement notation in case of “signed” format, using the following: Format IEC data type Description Bits Range INT16 Integer -32768 .. -
Page 8: Instantaneous Variables And Meters
Energy management Instantaneous variables and meters MODBUS: read only mode with functions code 03 and 04 Table 2.3-1 Modicom Physical Length VARIABLE Data Notes address address (words) ENG. UNIT Format 300001 0000h V L1-N INT32 V L2-N INT32 300003 0002h 300005 0004h V L3-N... -
Page 9: Carlo Gavazzi Controls Identification Code
Energy management Carlo Gavazzi Controls identification code MODBUS: read only mode with functions code 03 and 04 limited to a word at a time Table 2.6-1 Modicom Physical Length VARIABLE Data Notes address address (words) ENG. UNIT Format 300012 000Bh... -
Page 10: Pulse Output Configuration Menu
Energy management 2.7.5 Pulse output configuration menu MODBUS: read read and write mode Modicom Physical Length VARIABLE Data Notes address address (words) ENG. UNIT Format 1007h Kwh per pulse UINT 16 Value min = 1 (0,01Kwh) 304104 Value max = 999 (9,99KWh) 2.7.6 Serial port configuration menu MODBUS: read and write mode...