IAI America ROBO Cylinder Series - Manual (Page 64)

5. Modbus RTU
56
Modbus
5.1 Message Frames (Query and Response)
Start Address Function code Data CRC Check End
Silent
interval
1 byte 1 byte n byte 2 byte
Silent
interval
(1) Start
This field contains a silent interval (non communication time) of 3.5 characters or longer.
(1 character = 10 bits)
Example: In case of 9600 bps, (10 x 3.5) bits x 1/9600 bps = 3.65 ms
Note If the response timeout error occurs, change parameter No. 45, “Silent interval
multiplier” or No. 17, “Min. delay for activating local transmitter” using the IAI teaching
tool as required.
(2) Address
This field specifies the addresses of connected RC controllers (01
H
to 10
H
).
Address = axis number + 1
Caution: The address is not equal to the corresponding axis number: be careful when
making settings.
(3) Function
The table below summarizes the function codes and functions that can be used with RC
controllers.
Code
[Hex]
Name Function
01
H
Read Coil Status Read coils/DOs.
02
H
Read Input Status Read input statuses/DIs.
03
H
Read Holding Registers Read holding registers.
04
H
Read Input Registers Read input registers.
05
H
Force Single Coil Write one coil/DO.
06
H
Preset Single Register Write holding register.
07
H
Read Exception Status Read exception statuses.
0F
H
Force Multiple Coils Write multiple coils/DOs at once.
10
H
Preset Multiple Registers Write multiple holding registers at once.
11
H
Report Slave ID Query a slave’s ID.
17
H
Read / Write Registers Read/write registers.
Note This manual explains about mark function codes.
(Reference) The ROBONET gateway supports three types of function codes (03
H
, 06
H
and
10
H
).
[Please refer to the separate ROBONET Operation Manual.]