R7M-DAC16C
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-7803-AK Rev.4 P. 7 / 8
MODBUS FUNCTION CODES & SUPPORTED CODES
■
Data and Control Functions
CODE
NAME
01
Read Coil Status
Digital output from the slave (read/write)
02
Read Input Status
Status of digital inputs to the slave (read only)
03
Read Holding Registers
General purpose register within the slave (read/write)
04
Read Input Registers
Collected data from the field by the slave (read only)
05
Force Single Coil
Digital output from the slave (read/write)
06
Preset Single Register
General purpose register within the slave (read/write)
08
Diagnostics
11
Fetch Comm. Event Counter
Fetch a status word and an event counter
12
Fetch Comm. Event Log
A status word, an event counter, a message count and a field of event bytes
15
Force Multiple Coils
Digital output from the slave (read/write)
16
Preset Multiple Registers
General purpose register within the slave (read/write)
17
Report Slave ID
Slave type/ ‘RUN’ status
■
Exception Codes
CODE
NAME
01
Illegal Function
Function code is not allowable for the slave
02
Illegal Data Address
Address is not available within the slave
03
Illegal Data Value
Data is not valid for the function
■
Diagnostic Subfunctions
CODE
NAME
00
Return Query Data
Loop back test
MODBUS I/O ASSIGNMENT
ADDRESS
DATA TYPE
DATA
Coil (0X)
1 – 16
Digital Output (discrete output of the basic module)
17 – 32
Digital Output (discrete output of the extension module)
Inputs (1X)
1 – 16
Digital Input (discrete input of the basic module)
17 – 32
Digital Input (discrete input of the extension module)
33 – 48
Reserved (unused)
49 – 64
Module Status
65 – 80
Reserved (unused)
Input Registers (3X)
1 – 4
I
Analog Input
5 – 16
----
Reserved (unused)
17 – 24
F
Analog Input
25 – 48
----
Reserved (unused)
Holding Registers (4X)
1 – 2
I
Analog Output
3 – 16
----
Reserved (unused)
17 – 20
F
Analog Output
21 – 48
----
Reserved (unused)
I: Integer, -1500 – +11500 (-15 – +115%)
F: Floating
Note: DO NOT access addresses other than mentioned above. Such access may cause problems such as inadequate operation.
