EKO INSTRUMENTS CO., LTD. - Pyranometer MS-60/60S - Instruction Manual Ver. 4
Pg. 16
2-3. How to Connect Communication with Modbus RTU
MS-60S can connect to a system that communicates with Modbus RTU by using RS-485.
Maximum of 100 units can be connected, and individual address can be assigned.
Connection of MS-60S to the RS-485 communication network is shown below.
Master represents the data logging device [such as PC], and slaves represent devices such as
MS-60S.
Connect the + and
– for the master to [A] and [B] for each MS-60S. Also at the end of network,
connect a 120
Ω termination resistor.
Modbus address is the last 2 digits of the product serial number. If the last 2 digits are
“00”, the
address will be
“100”.
[*]Communication errors may occur depending on the connection distance and the number of
connections. In that case, please use RS485 booster or repeater.
Figure 5-4. Communication Connection with Modbus RTU
2-4.
How to Connect Communication with SDI-12
Connect the output cable terminal to voltmeter or data logger with corresponding wire colors
described below. Make sure the cable length between the connecting slave [such as
pyranometers] and data collecting device to be less than 60m. Shield must be connected, or
noise may occur.
Also see 7-3. Output Cable for cable arrangements.
Figure 5-5. Communication Connection with SDI-12
SDI-12 Data
DC-12V+
Ground
Slave
No.n
Slave
No.1
Slave
No.2
Slave
No. 3
Data collection
Device