Instruction Manual

5. Modbus RTU
114
Modbus
(4) Query sample
An example of use is shown, where the current measurement on the load cell connected to
controller axis 0 is read.
z Query (silent intervals are inserted before and after the query)
01 03 90 0A 00 02 89 0D
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Start address [H] 901E
Number of registers [H] 0002
Error check [H]
890D (in accordance with
CRC calculation)
End Silent interval
The response to the query is as follows.
z Response (silent intervals are inserted before and after the response)
01 03 04 00 00 03 E4 FA 88
Field RTU mode
8-bit data
Start Silent interval
Slave address [H] 01
Function code [H] 03
Number of data bytes [H] 04 (4 bytes = 2 register)
Data 1 [H] 00 00 03 E4
Error check [H]
FA88 (in accordance with CRC
calculation)
End Silent interval
Example 1) The current measurement on the load cell is “000003E4,”convert into a decimal
number, or 996 (x 0.01 N) o The current push force is 9.96 N.
Example 2) If the current measurement reading on the load cell is “FFFFFF35”
(tensile state
(Note 2)
), the formula FFFFFFFF
H
– FFFFFF35
H
+ 1 (1 must be added)
applies.
The result is converted into decimal number, or 203 (x 0.01 N) o
The current tensile force
(Note 2)
is 2.03 N.
Note 1 This is only one example of response. The specific response varies depending on
each situation.
Note 2 Load cell cannot be used for pulling operation.