Modbus Function And Register Assignments; Modbus Client/Master Function - YOKOGAWA SMARTDAC+ GX10 User Manual

4.5

Modbus Function and Register Assignments

4.5.1

Modbus Client/Master Function

IM 04L51B01-01EN
Function
The GX/GP supports the following functions.
The server (slave) must support these functions.
Function Code Function
1 Read the coil status
(0xxxx)
2 Read the input relay
status (1xxxx, 1xxxxx)
3 Read the hold register
(4XXXX, 4XXXXX)
4 Read the input register
(3XXXX, 3XXXXX)
5 Change the single coil
status
(0xxxx)
6 Write to a single hold
register (4xxxx, 4xxxxx)
15 Change the coil status
(0xxxx)
16 Write to the hold register
(4XXXX, 4XXXXX)
Command
Command type: Read, Write
Number of commands: GX20-1/GP20-1: Set up to 100 commands
GX20-2/GP20-2: Set up to 200 commands
GX10/GP10: Set up to 50 commands
Data type: See the table below.
Symbol Description
INT16 16-bit signed integer
UINT16 16-bit unsigned integer
INT32_B 32-bit signed integer (big endian)
INT32_L 32-bit signed integer (little endian)
UINT32_B 32-bit unsigned integer (big endian)
UINT32_L 32-bit unsigned integer (little endian)
FLOAT_B 32-bit floating point (big endian)
FLOAT_L 32-bit floating point (little endian)
BIT Bit
Special value output
When a register is read or when its content is exported through the Modbus function, the
GX/GP may output the following special values.
Channel status
+Over, +Burnout
–Over, –Burnout
Example: Channel status is "–Over"
Data type
INT16
INT32
FLOAT
Operation
The GX/GP reads the coil status of the server (slave)
device.
The GX/GP reads the input relay status of the server
(slave) device.
The GX/GP reads the hold register of the server
into a communication channel.
The GX/GP reads the input register of the server
into a communication channel.
The GX/GP changes the single coil status of the server
(slave) device (off/on).
The GX/GP writes to a single hold register of the server
(slave)
.
The GX/GP changes the coil status of the server (slave)
device (off/on).
The GX/GP writes the I/O channel data, math channel
data, or communication channel data to the hold register
of the server (slave).
Data type
Integer
Maximum expressible value
Minimum expressible value
Output value
–32768 (0x8000)
–2147483648 (0x80000000)
–∞ (0xff800000)
(slave)
(slave)
Floating
+∞
–∞
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5
App
Index