User manual

Termination jumpers
(shown
in "disabled" position)
4664
Modbus slave port terminal blocks
Address switch
Figure 6‑10. Termination jumpers on the communications interface PCB
The performance of your Modbus network may require each end of the network to be
terminated using 120 Ω termination resistors. When the network is long, relative to
the RS-485 bit rate in use, bus terminations must be installed. The network length is
determined by the total backbone cable length and not necessarily the line-of-sight
between the two furthest apart devices.
Table 6‑1. Maximum network length per Modbus bit rate
RS-485/Modbus Bit
Rate
Maximum Network
Length Without
Termination in Feet
(Meters)
Maximum Network
Length With Termination
in Feet (Meters)
9600 bps 1000 (305) 4000 (1200)
19,200 bps 500 (152) 4000 (1200)
38,400 bps 250 (76) 4000 (1200)
57,600 bps 150 (46) 4000 (1200)
TO TERMINATE THE INVERTER NETWORK
If bus termination is desired and the inverter is on the end of the Modbus network,
you need to set the termination.
1.
Verify that the J7 jumper is in the lowe, NC position.
2. Move the jumper to the upper pair of J11 pins labeled Line.
3. Verify that the J10 jumper is in the lower NC position.
Advanced Energy
6‑12 Data Monitoring and Controls 570-1001792-05A