Satec PM130 User Manual

7
3 MODBUS MESSAGE FORMATS
3.1 Function 03 - Read Multiple Registers
This command allows the user to obtain contents of up to 125 contiguous registers from a
single data table.
Request
Instrument
Address
Function
(03)
Starting
Address
Word Count Error Check
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Starting Address
Address of the first register to be read
Word Count
The number of contiguous words to be read
Response
Instrument
Address
Function
(03)
Byte
Count
Data
Word 1
... Data
Word N
Error
Check
1 byte 1 byte 1 byte 2 bytes ... 2 bytes 2 bytes
The byte count field contains quantity of bytes to be returned.
3.2 Function 04 - Read Multiple Registers
This command allows the user to obtain contents of up to 125 contiguous registers from a
single data table. It can be used instead of function 03.
Request
Instrument
Address
Function
(04)
Starting
Address
Word Count Error Check
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Starting Address
Address of the first register to be read
Word Count
The number of contiguous words to be read
Response
Instrument
Address
Function
(04)
Byte
Count
Data
Word 1
... Data
Word N
Error
Check
1 byte 1 byte 1 byte 2 bytes ... 2 bytes 2 bytes
The byte count field contains quantity of bytes to be returned.
3.3 Function 06 - Write Single Register
This command allows the user to write the contents of a data register in any data table where a
register can be written.
Request
Instrument
Address
Function
(06)
Starting
Address
Data
Word
Error
check
1 byte 1 byte 2 bytes 2 bytes 2 bytes
Starting Address
Address of the register to be written
Data Value
Data to be written to the register

Satec PM130 Specifications

General

Frequency Measurement Range	45 to 65 Hz
Power Supply	85-265V AC/DC, 100-300V DC
Display	LCD
Communication	RS485
Digital Inputs	2
Digital Outputs	2
Protocols	Modbus RTU
Accuracy	0.2% of reading
Power Accuracy	0.5%