Yokogawa PR300 Power and Energy Meter - Manual (Page 68)

<Toc> <Ind> <4. PC Link Communication Protocol>
4-7
IM 77C01E01-10E
WRD Reads D registers on a word-by-word basis
●
Function
This function code reads a sequence of contiguous register information on a word-by-word
basis by the specified number of words, starting with a specified register number.
• The number of words to be read at a time is 1 to 64.
• For the format of response in the event of failure, see subsection 4.1.2.
• The command shown below includes the checksum function. When performing
communication without the checksum, do not include the 2-byte checksum element in
the command.
●
Command/Response (for normal operation)
The response is returned in a 4-digit character string (0000 to FFFF) in hexadecimal.
ddddn: read data of the specified number of words
ddddn = character string in hexadecimal
n = 1 to 64 words
Number of
Bytes
Response
element
1
STX
3
WRD
2
Station
number
(ST-NO)
2
01
4
dddd1
4
dddd2
4
ddddn
2
OK
…
…
2
Checksum
1
ETX
1
CR
Number of
Bytes
Command
element
1
STX
2
Station
number
(ST-NO)
2
01
1
Comma
or
space
2
Number
of words
(n)
1
0
2
Checksum
5
Register
number
1
ETX
1
CR
●
Example
Read the active energy (register symbol: kWh L and kWh H) of the PR300 at station num-
ber 01.
The register numbers for active energy are D0001 and D0002.
[Command]
[STX]01010WRDD0001, 0272 [ETX] [CR]
The data of active energy (2 words) will be returned in response to the command above.
[Response]
[STX]0101OK7840017D0B [ETX] [CR]
25000000 [kWh] in decimal.
See the Note below.
Note: To use the response data as the reading, reverse the order of the upper and lower words.
Hex 7840 017D → (reversed) → Hex 017D 7840 → Decimal 25000000