Energy Meter Manual

4-12
<Toc> <Ind> <4. PC Link Communication Protocol>
IM 77C01E01-10E
WRM Monitors the D registers on a word-by-word basis
● Function
This function code reads the information of the registers that have been specified in ad-
vance by the WRS command.
• Before executing this command, the WRS command must always be executed to
specify which registers are to be monitored. If no register has been specified, error
code 06 is returned.
• 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 number of words specified by the WRS command
ddddn = character string in hexadecimal
n = 1 to 32 words
Number
of Bytes
Command
element
1
STX
2
Station
number
(ST-NO)
2
01
3
WRM
1
0
2
Checksum
1
ETX
1
CR
Number
of Bytes
Response
element
1
STX
2
Station
number
(ST-NO)
2
01
4
dddd1
4
dddd2
4
ddddn
2
OK
…
…
2
Checksum
1
ETX
1
CR
● Example
Monitor the active power (register symbol: W L and W H) of the PR300 at station number
01. (This command reads the status of the register specified by the WRS command.)
[Command]
[STX]01010WRME8[ETX][CR]
The data 2500 will be returned in response to the command above.
[Response]
[STX]0101OK4000451CF9[ETX][CR]
Note: To use the response data as the reading, reverse the order of the upper and lower words.
Active power: floating-point hex data 4000 451C→ (reversed) → Hex 451C 4000 ⇒ Decimal 2500