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ANNEX A
A.1
Characteristics of the MICROVIP3 PLUS
Rs232 serial communication software
protocol
The software communication protocol complies with the ASCII (7 bits) MODBUS protocol.
- Selected transmission mode: ASCII
- Coding system: HEX (uses printable ASCII
characters: 0-9, A-F).
- Error detection mode: LRC
- Serial protocol characteristics:
- Baud rate:
1200, 2400, 4800, 9600, 19200, 38400
- Data bits:
7/8
- Parity bits:
None/Odd/Even
- Stop bits:
1/2
The commands implemented by the MODBUS protocol are:
• Reading of all measurements
• Date and time reading
• Disabling/enabling of the keyboard
• Power peaks and averages reset
• Energy meters reset
• Programming of current transformer ratios
• Programming of voltage transformer ratios
• Selection of the three-phase system type:
STAR/DELTA
• Selection of option: STANDARD1,
STANDARD2, COGENERATION4
• Programming of the integration time for average
values
• Data and time programming
List of MODBUS protocol commands implemented and their limitations
READING OF N. WORDS
P.C.
MICROVIP3 PLUS
:,AA,03H,SSSS,WWWW,LRC,CR,LF
- - - - - - ->
<- - - - - - -:,AA,03H ,BB,D1,..,Dn,LRC,CR,LF
where:
- AA
= 01 = address of the MICROVIP3 PLUS (2 bytes ASCII)
- 03H
= Code of the command for reading of N words (2 bytes ascii)
- SSSS
= Address from which the reading starts (4 bytes ascii)
- WWWW
= Number of words to be read (4 bytes ascii): max. 70 words
- LRC
= Longitudinal Redundancy Check (2 bytes ascii)
- CR
= 0DH (1 byte ascii)
- LF
= 0AH (1 byte ascii)
- BB
= Number of bytes read (2 bytes ascii)
- D1,..,Dn
= Bytes of data read (2 * Num.ascii bytes)
COMMANDS IMPLEMENTED:
- Eeprom reading
(0000H <= SSSS <= 00FEH; Valid range: 0000H-00FFH NOTE::
The address must always be even)
- Internal RAM reading
(SSSS = 0810H)
- External RAM reading
(SSSS = 0FE00H)
