Mitsubishi Electric ECOV-X37VA Manuel D'installation page 47

[3] Connecting the communication devices
Connect the Modbus communication devices with cables.
Daisy-chain the Modbus communication devices as shown in Figure 3-1.
Communication may not be established properly if the devices are connected in the star wiring configuration or branched
from the module as shown in Figure 3-2.
Correct wiring
(Daisy-chain)
Incorrect wiring
(Star wiring)
Incorrect wiring
(Branched
connections)
[4] Connecting the terminating resistor
When this unit is at the end of the network, connect the supplied terminating resistor (120 Ω) to the unit.
The terminating resistor is packaged in the control box.
Device at the end
of network
Maximum communication distance: 1200 m
Figure 3-1 Example of correct wiring between communication devices
Device at the end
of network
Device at the end
of network
Figure 3-2 Examples of incorrect wiring between communication devices
47
Device at the end
of network
Device at the end
of network
Device at the end
of network
WT09614X03_GB