Nor-Cal SDC15 Controller - Manual (Page 167)

7-9
■ Fixed length continuous data write command (WD command)
This command writes continuous data in two-byte units. This command is suitable
for handling data in ladder programs sent by PLC communications as the data is of
a fixed length.
The start data address is expressed as four hexadecimal digits. Data is expressed
as four X n (n is a positive integer) hexadecimal digits.
● Send message
The write start data address (four hexadecimal digits) and the write data count
(four X n hexadecimal digits) are sent.
● Response message
If writing is successful, the normal termination code (two decimal digits) is
returned. If only part of the data is written, and the remaining data is not written,
the warning termination code (two decimal digits) is returned. If none of the data
is written, the abnormal termination code (two decimal digits) is returned.
● Maximum read data count per message
RAM area: Up to 27 words
EEPROM area: Up to 16 words
Chapter 7. CPL COMMUNICATIONS FUNCTIONS
W
• Writing of single data item
D
• Writing of multiple data items
(1) Fixed length continuous data write command
(2) Start data word address
(3) Data 1
(4) Data 2 to data (n-1)
(5) Data n
(1) (2) (3)
(5)
W
(1)
D
(2) (3) (4)
0
• Normal termination
(1)
0
• Abnormal termination or warning
X
(1)
X The abnormal termination code is entered at XX.
For details of codes,
refer to
7-6, List of Termination Codes (on page 7-14).
(1) Termination code