66
9
RS-485 INTERFACE
66
R
S-4
85
IN
TE
R
FA
C
E
Chapter
9
■
Function codes for Modbus
Function codes are explained in detail.
In this chapter, function fields and data fields varying by function codes are explained.
Each actual message frame consists of an address field, function field, data field, and error check
field, which are transmitted in this order.
List of function codes
01 (0x01) Read coils
ON/OFF states of slave coils are read.
Since this is a read command, no broadcast can be specified.
Specify the coil start address and number of coils.
* N = Number of coils/8 or N = N + 1 if indivisible
Example) Read the digital zero (address 00005) state.
Code
Function name
Command
01 (0x01)
Read coils
Read out coils
02 (0x02)
Read discrete inputs
Read out input statuses
03 (0x03)
Read holding registers
Read out holding registers
04 (0x04)
Read input register
Read out the input register
05 (0x05)
Write single coil
Write in a coil (single)
06 (0x06)
Write single register
Write in a holding register (single)
15 (0x0F)
Write multiple coils
Write in coils (multiple)
16 (0x10)
Write multiple registers
Write in holding registers (multiple)
08 (0x08)
Diagnostics
Diagnosis mode
11 (0x0B)
Get comm event counter
Read out the event counter
12 (0x0C)
Get comm event log
Read out communication events
17 (0x11)
Report slave ID
Read out slave ID information
[Request]
Function
1
byte
0x01
Start address
2
bytes
0x0000 - 0xFFFF
Number of coils
2
bytes
1 - 2000 (0x07D0)
[Response]
Function
1
byte
0x01
Number of data bytes
1
byte
N *
Coil status
n
bytes
N or N+1
[Error response]
Error code
1
byte
0x81 (fu 0x80)
Exception code
1
byte
01 or 02 or 03
[Request]
Function
01
[Response]
Function
01
Start address; higher
00
Number of data bytes
01
Start address; lower
04
Digital zero
00
Number of coils; higher
00
Number of coils; lower
01
Summary of Contents for F701-P
Page 1: ...01AUG2020REV 1 07 WEIGHING INDICATOR F701 P OPERATION MANUAL...
Page 11: ...Contents X Contents X M E M O...
Page 116: ......