73
6
. Detailed settings for communications
6.2 Modbus (continued)
●
Service details
■
Variable area read (03: H’03)
This service allows you to read all variable areas.
Reading of the variable areas is conducted by setting the required data in the following command frame.To read
setting values "Parameter area list (
95)", you need to first move to the setting mode with a command. To read
measurement values "List of variable areas (measurement values) (
93)", you can be in either the measuring mode
or the setting mode. Also, measuring continues even while in the setting mode.
Command frame
• Start reading address
Specify the address for the measurement value or
setting data you want to read. Refer to "6.4 Address
map
)
" for the address.
• Number of elements
Specify the number of pieces of data that you want to
read times 2 as the number of elements.
Range: H’0002 to 0032 (2 to 50).
• CRC-16
This is a check code calculated from the
communication address until the end of the data.
Refer to "An example for CRC-16 calculation" for the
calculation. (
Commu
nication
address
Function
code
Start reading
address
Number of
elements
CRC-16
H’03
1
1
2
2
2
