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TriStar MPPT 600V Operator’s Manual
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Troubleshooting
If the LED indications are normal, check the fuses, breakers, and wiring connections in the power
source wiring. With a multi-meter, check the array voltage directly at the TriStar MPPT 600V solar
input terminals. Solar input must be greater than 100 Volts before charging will begin.
Problem:
Controller makes buzzing and humming noises.
Solution:
No action is required. This is expected due to magnetic resonance and circuit switching.
6.2 Network and Communications Issues
Problem:
Cannot connect to the controller via RS-232
Solution:
Check the following:
• The RS-232 cable is straight-through, not a Null Modem (cross-over)
• If using a serial-USB adapter, verify that the adapter software is installed and a serial COM
port has been mapped. Check the activity light on the USB adapter if it has one. If there is
no activity, the wrong COM port has been chosen or there is a configuration issue with the
adapter.
• The default MODBUS ID of the TriStar MPPT 600V is 1. Verify that the PC software is
configured to communicate using the correct ID.
Problem:
Cannot connect to the controller via EIA-485
Solution:
Check the following:
• The RS-232 port is not in use. The EIA-485 and RS-232 ports cannot be used simultane-
ously. Only one port can be used at a time.
• The RSC-1 adapter used to connect the PC to the EIA-485 network shows a green LED
and pulses red when a connection is attempted. See the RSC-1 documentation for more
information.
• Each controller or device on the EIA-485 network has been programmed with a unique
MODBUS ID.
• A serial cross-over (Null Modem) cable is used for the connection between the PC and the
Morningstar RSC-1 485 Adapter. A straight-through serial cable will not work.
• Power is supplied to the 4-wire bus on the Power/Ground lines. The bus requires voltage
in the range: 8 - 16 Vdc.
• All bus connections are secure and each terminal is wired in parallel: line A to line A, line B
to line B, etc.
Problem:
Cannot connect to the controller via Ethernet
Solution:
See the, “Morningstar Communications Document”, available at:
http://morningstarcorp.com/support
