YOKOGAWA UPM100, User Manual

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4-13
IM 77C01H01-10EN
PC Link Communication
4
WRD Reads D registers and I relays on a word-by-word basis
Function
Reads a sequence of contiguous register information on a word-by-word basis by the
specified number of words, starting at the 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.
• Specify the leading I relay number to read I relays on a word-by-word basis. Data of 16
bits starting at the leading I relay are to be read.
Command/Response (for normal operation)
Number
of Bytes
1 2 2 1 3 5 1 2 2 1 1
Command
element
STX
Station
number
(ST-NO)
CPU
number
(01)
Time to
wait for
response
(0)
WRD Register
number
Comma
or
space
Number
of words
(n)
Checksum ETX CR
Number
of Bytes
1 2 2 2 4 4 … 4 2 1 1
Response
element
STX
Station
number
(ST-NO)
CPU
number
(01)
OK dddd1 dddd2 … ddddn Checksum ETX CR
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
Example
Read the active energy (register symbol: kWh L and kWh H) of the UPM100 at station
number 01.
The following command reads the active energy (D0001 and D0002).
[Command]
[STX]01010WRDD0001, 02A2 [ETX] [CR]
The data of active energy (2 words) is returned in response to the above command.
[Response]
[STX]0101OK7840017DA9 [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
4.2 Command and Response