
R30NE1
5-2-55, Minamitsumori, Nishinari-ku, Osaka 557-0063 JAPAN
Phone: +81(6)6659-8201 Fax: +81(6)6659-8510 E-mail: [email protected]
EM-9019 Rev.1 P. 6 / 10
MODBUS FUNCTION CODES & SUPPORTED CODES
■
DATA AND CONTROL FUNCTIONS
CODE
NAME
01
Read Coil Status
X
Digital output from the slave (read/write)
02
Read Input Status
X
Status of digital inputs to the slave (read only)
03
Read Holding Registers
X
General purpose register within the slave (read/write)
04
Read Input Registers
X
Collected data from the field by the slave (read only)
05
Force Single Coil
X
Digital output from the slave (read/write)
06
Preset Single Register
X
General purpose register within the slave (read/write)
07
Read Exception Status
08
Diagnostics
X
09
Program 484
10
Poll 484
11
Fetch Comm. Event Counter
X
Fetch a status word and an event counter
12
Fetch Comm. Event Log
X
A status word, an event counter, a message count and a field of event
bytes
13
Program Controller
14
Poll Controller
15
Force Multiple Coils
X
Digital output from the slave (read/write)
16
Preset Multiple Registers
X
General purpose register within the slave (read/write)
17
Report Slave ID
X
Slave type / ‘RUN’ status
18
Program 884/M84
19
Reset Comm. Link
20
Read General Reference
21
Write General Reference
22
Mask Write 4X Register
23
Read/Write 4X Register
24
Read FIFO Queue
■
EXCEPTION CODES
CODE
NAME
01
Illegal Function
X
Function code is not allowable for the slave
02
Illegal Data Address
X
Address is not available within the slave
03
Illegal Data Value
X
Data is not valid for the function
04
Slave Device Failure
05
Acknowledge
06
Slave Device Busy
07
Negative Acknowledge
08
Memory Parity Error
■
DIAGNOSTIC SUBFUNCTIONS
CODE
NAME
00
Return Query Data
X
Loop back test
01
Restart Comm. Option
X
02
Return Diagnostic Register
X
03
Change Input Delimiter Character
X
04
Force Slave to Listen Only Mode
X