Omron E5AC, Руководство по связи

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4 Modbus Communications Procedure
4 - 10
E5@C Digital Temperature Controllers Communications Manual (H175)
To write data to the variable area, set the required data in the command frame, as shown in the follow-
ing diagram.
Command Frame
4-4-2 Variable Write, Multiple
Name Description
Slave address Specify the E5
@
C's unit number.
The unit number can be set between H'01 and H'63 hexadecimal (1 to 99 decimal).
Function code The Write Variable Area function's function code is H'10.
Write start address Specify the starting address where the setting data will be written.
Refer to
Section 5 Communications Data for Modbus
for details on addresses.
Number of elements 4-byte Mode
Specify 2 times the number of setting data items as the number of elements to be
written.
The setting range for the number of elements is H'0002 to H'0068 (2 to 104).
When H'0068 is set, 52 items of setting data can be read.
Example: When writing 2 items of setting data, set the number of elements to
H'0004.
2-byte Mode
Specify the number of setting data items to be written as the number of elements.
The setting range for the number of elements is H'0001 to H'0068 (1 to 104).
When H'0068 is set, 104 items of setting data can be read.
Example: When reading two items of setting data, set the number of elements to
H'0002.
Byte count Specify the number of bytes of write data.
CRC-16 This check code is calculated with the data from the slave address to the end of the
data.
For details on the CRC-16 calculation, refer to
CRC-16 Calculation Example
in
4-1-1
Command Frame
on page 4-2.
1 2 1 2 1
CRC-16
2
Number of
Elements
Slave
address
Function
code
Write start address Byte count
H'10
0 to 208 (2
×
104)
Write data (for the number of
elements)