Supported Modbus-Rtu Functions; Frame Format: Read Coil - Uponor Smatrix Base PRO Controller X-147 Installation Manual

2 Supported Modbus-RTU functions

The Base PRO controller supports the following functions for
Modbus-RTU communication.
Description
Read Coil
Read Discrete Input
Read Holding Registers
Read Input Registers
Write Single Coil
Write Single Holding Register
Write Multiple Coils
Write Multiple Holding Registers
• Discrete Inputs (read only) and Coils (read and write) are
function codes consisting of 1 bit of data. Most often on or off.
• Input Registers (read only) and Holding Registers (read and
write) are function codes consisting of 2 bytes (16 bit) of data.
Most often temperature data or settings.

2.1 Frame format: Read Coil

Request
Slave address Function code
(0x01 – 0xF7) (0x01)
1 byte 1 byte
Response
Slave address Function code
(0x01 – 0xF7) (0x01)
1 byte 1 byte
Response in case of error
Slave address Error code
(0x01 – 0xF7) (0x81)
1 byte 1 byte
Example:
Request example:Read Heating/Cooling and Comfort/ECO states
Slave address Function code
(0x01) (0x01)
1 byte 1 byte
Response example:Read Heating/Cooling and Comfort/ECO states
Slave address Function code
(0x01) (0x01)
1 byte 1 byte
Function code (hex)
0x01
0x02
0x03
0x04
0x05
0x06
0x0F
0x10
Starting register address
(0x0000 – 0xFFFF)
2 bytes
Byte count
(N)
1 byte
Exception code
(01, 02, 03, 04, or 06)
1 byte
Starting register
address HI
(0x00)
1 byte
Byte count
(0x01)
1 byte
Uponor Smatrix Base PRO Controller X-147 Modbus RTU interface
Number of coils to read
(1 – 2000)
2 bytes
Coil status
(n = N, or n=N+1 if the number of coils to
read can be divided by 8 with a reminder
separated from 0)
n bytes
Starting register Number of coils to
address LO read HI
(0x00) (0x00)
1 byte 1 byte
Coil status
1 to 8 (0x02)
1 byte
CRC
2 bytes
CRC
2 bytes
CRC
2 bytes
Number of coils to CRC
read LO
(0x02)
1 byte 2 bytes
CRC
2 bytes
| Installation manual | 7