IAI America ROBO Cylinder Series - Manual (Page 85)

5. Modbus RTU
77
Modbus
5.3.7 Current Position Reading <<PNOW>> (in 0.01 mm units)
(1) Function
This bit reads the current position in units of 0.01 mm. The sign is effective.
(2) Query format
Field Number of data items
(number of bytes)
RTU mode
8-bit data
Remarks
Start None Silent interval
Slave address [H] 1 Arbitrary Axis number + 1 (01
H
to 10
H
)
Function code [H] 1 03 Register reading
Start address [H] 2 9000 Current position monitor
Number of registers [H] 2 0002 Reading addresses 9000
H
to
9001
H
Error check [H] 2 CRC (16 bits)
End None Silent interval
Total number of bytes 8
(3) Response format
A response message contains 16 bits of data per register.
Field Number of data items
(number of bytes)
RTU mode
8-bit data
Remarks
Start None Silent interval
Slave address [H] 1 Arbitrary Axis number + 1 (01
H
to 10
H
)
Function code [H] 1 03 Register reading
Number of data bytes [H] 1 04 Reading 2 registers = 4 bytes
Data 1 [H] 2 In accordance with
the current position
data
Current position data [Hex]
(most significant digit)
Data 2 [H] 2 In accordance with
the current position
data
Current position data [Hex]
(least significant digit)
Error check [H] 2 CRC (16 bits)
End None Silent interval
Total number of bytes 9