EKO INSTRUMENTS CO., LTD Modbus Signal Converter MC-20 Instruction Manual V5 Pg. 9
5-2. Setup
1. Installation
1) MC-20 where it will not get wet or get soaked in water.
2) Keep MC-20 away from direct sunlight.
3) Use provided double sems screws incase the converter is installed on installation base with screws.
The maximum torque for tightening the sems screws is 0.4N・m.
NOTE: MC-20 is paired with the pyranometer which is purchased together; when connecting with the
pyranometer, make sure to connect with the right pyranometer. Use the pyranometer with same serial
number stated on the MC-20 inspection report.
Install the Signal Converter MC-20 after installing the pyranometer.
NOTE: In industrial environments to reduce potential EMI effects, the cable between pyranometer and
converter need to be less than 1m.
NOTE: Make sure that the power supply is switched off during installation of the pyranometeroutput cable.
2. Electrical Connection
1) Connect the attached L-Shaped tab terminals (male) to the terminal numbers 1 through 6 on the
converter.
2) Attach the provided plug-type crimping terminals (female) to the input and power supply cable ends by
crimping. ( Please use crimping tool that is for crimping terminal with insulating coating applicable for
1.25mm
2
)
3) Attach the attached pin terminals to the RS485 communication line ends by crimping. There are 3
communication line: (+), (-), and (G).
(Please use crimping tool that is for crimping terminal (with insulating sleeve pin terminal) applicable for
0.5mm
2
).
4) Connect the L-Shaped tab terminal (male) attached to the MC-20 and plug-type crimping terminals
(female) together, and connect the crimping terminal for communication terminal to Communication
Control Terminal (+) and (-), as well as to grounding terminal.
5) Follow Figure 5-3 for wiring. (Depending on the measurement mode, the signal input terminal wiring
method changes. See Figure 5-4.) When connecting to devices such as PC, which has USB interface,
use RS-485/USB converter. Recommended power supply voltage is DC 24V.
NOTE: When taking measurement with 2-wire Pt-100, error in temperature measurement will occur due to
the resistance values between the wires in Pt-100 cable. To minimize the measurement error, make the
cable length as short as possible.
(Example) In case the EKO Radiation Shield with Temperature Sensor MT-052-A is connected with MC-20,
the measurement error per meter for MT-052 cable: 0.33℃
6) Prepare a 0.5A fuse, and connect it to power supply line in series. Depending on the connecting power
supply, large amount of current will flow when internal malfunction occur and may lead to generating heat
and fire.
