Function, Command/response (for normal operation), Example – Yokogawa JUXTA M Series Digital Limit Alarms MVTK User Manual
Page 27

<3. PC Link Communication >
3-13
IM 77J04J11-01E 1st Edition : 2006.08.25-00
WRD Reads D registers and I relays on a word-by-word basis
●
Function
Reads a sequence of contiguous register data on a word-by-word basis by the specified
number of words, starting at 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 3.1.2.
•
The command shown below includes the checksum function.
When performing communication without checksum, do not include the 2-byte
checksum element in the command.
●
Command/Response (for normal operation)
Number of Bytes
• • •
1
2
2
2
4
4
4
2
1
1
CR
Response
element
STX
OK
dddd1
dddd2
ETX
Address
number
(ADR)
CPU
number
01
• • •
ddddn
Checksum
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 is a character string in hexadecimal.
n=1 to 64
Number of Bytes
1
2
2
1
3
5
1
2
2
1
1
Command
element
STX
Address
number
(ADR)
CPU
number
01
Register
number
Comma
or space
Number
of words
(n)
Checksum
0
WRD
ETX
CR
●
Example:
Reading the alarm-1 setpoint (D0101) of the M Series with address number 01.
[Command]
[STX]01010WRDD0101,0172[ETX][CR]
The alarm-1 setpoint 500 (01F4 [HEX]) is returned in response to the above command
(50.0 is expressed as 500).
[Response]
[STX]0101OK01F437[ETX][CR]
500 in decimal (Alarm-1 setpoint [A1] is 50.0.)