88
12
Interface
88
In
te
rf
ac
e
Chapter
12
01 (0x01) Read Coils
The ON/OFF status of slave coils is read.
Broadcast cannot be specified for read commands.
The start address of the coil and the number of coils is specified.
*1: N = Number of coils/8, N = N+1 in case division is not possible.
e.g.) The digital zero (address 00003) status is read.
Note that the relative address is 0x02 when reading the digital zero value.
The remaining bit is 0 when less than 8 bits.
*2: The F325 response (coil status) is constantly 0.
(The process is performed the moment the command is read.)
Consider the read/write of coil to be completed by the normal response from the function
codes 05 (0x05) Write Signal Coil or 15 (0x0F) Write Multiple Coils.
02 (0x02) Read Discrete Inputs
The ON/OFF status of discrete input is read.
Broadcast cannot be specified.
The start address of the input and the number of inputs is specified.
*: N = Number of inputs/8, N = N+1 in case division is not possible.
[Request]
Function
1 byte
0x01
Start address
2 byte
0x0000 to 0xFFFF
Number of coils
2 byte
1 to 2000 (0x07D0)
[Response]
Function
1 byte
0x01
Data bytes
1 byte
N *1
Coil status
N byte
*2
[Error response]
Error code
1 byte
0x81 (fu0x80)
Exception code
1 byte
01 or 02 or 03
[Request]
Function
01
[Response]
Function
01
Start address (HI)
00
Data bytes
01
Start address (LO)
02
Digital zero
00
Number of coils (HI)
00
Number of coils (LO)
01
[Request]
Function
1 byte
0x02
Start address
2 byte
0x0000 to 0xFFFF
Number of inputs
2 byte
1 to 2000 (0x07D0)
[Response]
Function
1 byte
0x02
Data bytes
1 byte
N *
Input status
N byte
0x00 to 0xFF
[Error response]
Error code
1 byte
0x82 (fu0x80)
Exception code
1 byte
01 or 02 or 03
