Communication Parameters:
Apogee Sensors communicate using the Modbus RTU variant of the Modbus protocol. The default communication
parameters are as follows:
Slave address: 1
Baudrate: 19200
Data bits: 8
Stop bits: 1
Parity: Even
Byte Order: Big-Endian (most significant byte sent first)
The baudrate and slave address are user configurable.
Valid slave addresses are 1 to 247. Setting the slave
address to 255 will trigger a reset event, and all settings will revert back to the original default, which is slave
address 1 (i.e. if a sensor with a slave address of 5 is changed to 0, it will revert to slave address 1).
(This will also
reset factory-calibrated values and should
NOT
be done by the user unless otherwise instructed.)
Read only registers (function code 0x3).
Float Registers
0
1
calibrated output
µmol m⁻² s⁻¹
2
3
detector millivolts
4
5
immersed output
µmol m⁻² s⁻¹
6
7
solar output
µmol m⁻² s⁻¹
8
9
Reserved for Future Use
10
11
device status
(1 means device is busy, 0 otherwise)
12
13
firmware version
Integer Registers
40
calibrated output
µmol m⁻² s⁻¹
(shifted one decimal point to the left)
41
detector millivolts (shifted one decimal point to the left)
42
immersed output
µmol m⁻² s⁻¹
(shifted one decimal point to the left)
43
solar output
µmol m⁻² s⁻¹
(shifted one decimal point to the left)
44
Reserved for Future Use
45
device status (1 means device is busy, 0 otherwise)
46
firmware version (shifted one decimal point to the left)
