Morningstar PROFESSIONAL Series User manual

RSC-1
RS-232 to EIA-485
Communications Adapter
Installation and Operation Manual
www.morningstarcorp.com

Morningstar Corporation 32 RS-232 / EIA-485 Communications Adapter
Dimensions
3.3 in
2.8 in
1.4 in
0.9 in 0.8 in
Figure 1. RSC-1 Dimensions.
Technical Specications
Power Input Voltage 8V - 16V
Self Consumption 8 - 16 mA
Baud Rate 9600 baud
EIA-485 Network Unit Load 1/4
Operating Temperature -40 C to +60 C
Storage Temperature -55 C to + 80 C
Humidity 100% N.C.
Enclosure IP20
Dimensions 72 x 35 x 22 mm
Weight 37 g (1.3 oz)
DIN Rail Compatibility 35 mm (1-3/8”)
Certications   CE,RoHS
Warranty 5 years
Features
Status
LED
PC-controller Switch
DIN rail
tabs
EIA-485
Connector
RS-232
Connector
1
3
2
4 5
Figure 2. RSC-1 Features.
1 - PC-controller Switch. Sets RS-232 serial input source.
Use LEFT-OFF for connecting the RS-232 side to a PC or PC
USB to RS-232 cable. Use RIGHT-ON for connecting the RS-
232 side to a device with a serial port.
2 - Status LED. Used for monitoring and diagnostics - see pp.
7-8
3 - 9-pin RS-232 connector (male). Use to connect serial
cable from PC or system device. An RS-232 ribbon cable with
low-proleconnectorsisincludedbutnotshown.
4 - Molded tabs for attachment to 35 mm standard DIN rail
5 - Removable four (4) position EIA-485 terminal

Morningstar Corporation 54 RS-232 / EIA-485 Communications Adapter
R1 R2
+
-
8 - 16 Vdc
Ground
Data A
Data B
Power
To Serial
Device
To Serial
Device
To Serial
Device
Figure 4. EIA-485 bus wiring
Step 2 - Termination Resistors
Termination resistors (R1 & R2) must be placed on both ends
ofthedatabusasshowningure4.Ifthecharacteristic
impedanceofthecommunicationcableisZo,then:
R1 = R2 = Zo
Checkthecommunicationcablespecicationsforthe
characteristic impedance.
The typical characteristic impedance of select cables are
showninTable1,below.
Mounting
The RSC-1 can be mounted on standard 35 mm DIN rail. Four
(4) tabs are molded into the bottom of the case. Slide the RSC-1
onto an open end of the DIN rail.
Figure 3. Mounting the RSC-1 to DIN rail
Wiring
Step 1 Daisy-chain EIA-485 Connections
RSC-1 adapters are daisy-chained together as shown in Figure
4. Twisted pair communication cable is highly recommended to
maintain data integrity.

Morningstar Corporation 76 RS-232 / EIA-485 Communications Adapter
• Use twisted pair communication cable for the EIA-485
bus.
• Do not run network cables in the same conduit or trough
 asthesystempowercablesorACwiring.Ingeneral, 
avoid running network cables in parallel with power cables.
• AMeterBustoSerialConverter(model:MSC)canbeused
to communicate with Morningstar products that do not
have a serial port. See MSC documentation for supported
products.
PWR
GND
A
B
Mornin gstarC orporation
RS-232 / EIA-485
Adapter
Model: RSC-1
RS-232 (DTE)
EIA-485
R o H S
PWR
GND
A B
Morn ingstar Corporation
RS-232 / EIA-485
Adapter
Model: RSC-1
RS-232 (DTE)
EIA-485
R oH S
Address
1
Serial Cable Serial Cable
Serial Cable
Serial Cable
Null Modem
12 Volt
-+
Address
2
Address
3
METERBU S
RS-232
PC MeterBus Adapter
IsolatedMeterBus to
Serial RS - 232
CommunicationsAd apter
Morningstar Corporation
Model: MSC
RJ-11 Cable
SunSaver -MPPT
Relay Driver
TriStar RSC-1
RSC-1 RSC-1
MSC
RSC -1
PWR
GND
A
B
Mornin gstarC orporation
RS-232 / EIA-485
Adapter
Model: RSC-1
RS-232 (DTE)
EIA-485
R o H S
PWR
GND
A
B
MorningstarCorporation
RS-232 / EIA-485
Adapter
Model: RSC-1
RS-232 (DTE)
EIA-485
R oH S
Figure 5. An example EIA-485 network (termination resistors not shown)
Status LED Indications
The Status LED indicates adapter power and network
communication.Table2,below,identieseachoftheindication
types.
Cable Type Characteristic Impedance
RS-485 single twisted pair 120 ohm
Category 5 Ethernet 100 ohm
Table 1. Characteristic impedances of select communication cables.
Step 3 - Serial RS-232 Connections
ConnectaMorningstarcontroller,inverter,oraccessorytothe
RS-232 port on the RSC-1 using a straight-through serial cable. A
low-proleserialribboncableisincludedwiththeRSC-1.
Use a Null Modem serial crossover cable to connect a PC (or
other DCE serial device) to the RSC-1. A Null Modem cable is not
included.
Step 4 - EIA-485 Bus Power
The EIA-485 network requires external power. The source volt-
agemustbebetween8-16Vdc.For12Voltsystems,thenetwork
can be powered directly from the system battery. Use a DC-DC
converterfor24,36,and48Voltsystems.  
CAUTION: Tapping power o of individual batteries in a battery
bank can cause a voltage imbalance. Damage to the batteries may
result. Always use a DC-DC converter if thenominal system voltage
is greater than 12 volts.
Network Rules
• EachMorningstarcontroller,inverter,andaccessoryon 
the network must be programmed with a unique Modbus
Address. Addresses can be programmed using
Morningstar’s MSView PC software.
• Do not wire more than 128 RSC-1 adapters on a single
EIA-485 network (RSC-1 is 1/4 Unit Load)
•

Morningstar Corporation 98 RS-232 / EIA-485 Communications Adapter
Status LED Indication Note
OFF No bus power or
reverse polarity
Check EIA-485 bus
power & polarity
Green PowerOK,no
data on network
WiringOK,Ready
for transmit / receive
Green /
Red Flicker Data on network Network OK
Orange Reversed A & B
data lines
Check network
wiring
Table 2. LED Indications
Inspection and Maintenance
The following inspections and maintenance tasks are
recommended at least two times per year for best performance.
9Tightenallterminals.Inspectforloose,broken,or 
corroded connections.
9Verify that all wire clamps and tie-downs are secure.
9Checkthattheadapterismountedinaclean, 
 protectedenvironment;freeofdirt,insects,nests, 
and corrosion.
9Verify LED indication is consistent with the present
system conditions.
WARRANTY
LIMITED WARRANTY - Morningstar Solar
Charge Controllers and Inverters
IntegratedSeriesproducts,SureSineFamily(Gen2)inverters
and other Morningstar Professional SeriesTMproducts,except the
SureSineTM-300Classic(Gen1)inverter,arewarrantiedtobefree
from defects in materials and workmanship for a period of FIVE (5)
years from the date of shipment to the original end user.Warranty
onreplacedunits,oreld-replacedcomponents,willbelimitedonly
to the duration of the original product coverage.
Morningstar Essentials SeriesTMproducts,andSureSineTM-300
Classic(Gen1)inverter,arewarrantiedtobefreefromdefectsin
materials and workmanship for a period of TWO (2) years from the
date of shipment to the original end user. Warranty on replaced
units,oreld-replacedcomponents,willbelimitedonlytothe
duration of the original product coverage.
Morningstarwill,atitsoption,repairorreplaceanysuchdefective
units.
WARRANTYEXCLUSIONSANDLIMITATIONS:
Thiswarrantydoesnotapplyunderthefollowingconditions:
•Damagebyaccident,negligence,abuseorimproperuse
• PV or load currents exceeding the ratings of the product
•Unauthorizedproductmodicationorattemptedrepair
• Damage occurring during shipment
•Damageresultingfromactsofnaturesuchaslightning,weather
extremes,orinfestation.
THE WARRANTY AND REMEDIES SET FORTH ABOVE ARE
EXCLUSIVEANDINLIEUOFALLOTHERS,EXPRESSOR
IMPLIED. MORNINGSTAR SPECIFICALLY DISCLAIMS ANY
ANDALLIMPLIEDWARRANTIES,INCLUDING,WITHOUT
LIMITATION,WARRANTIESOFMERCHANTABILITYAND

Morningstar Corporation 1110 RS-232 / EIA-485 Communications Adapter
FITNESS FOR A PARTICULAR PURPOSE. No Morningstar
distributor,agentoremployeeisauthorizedtomakeany
modicationorextensiontothiswarranty.
MORNINGSTAR IS NOT RESPONSIBLE FOR INCIDENTAL OR
CONSEQUENTIALDAMAGESOFANYKIND,INCLUDINGBUT
NOTLIMITEDTOLOSTPROFITS,DOWN-TIME,GOODWILLOR
DAMAGE TO EQUIPMENT OR PROPERTY.
CLAIM PROCEDURE:
Beforerequestingwarrantyservice,checktheoperator’smanual,
includinganytroubeshootingsection,toverifyproductfailure.To
beginthewarrantyreplacementprocess,contactyourauthorized
Morningstar distributor or dealer for assistance with troubleshooting
and,ifnecessary,obtaininganRMAnumber.
An RMA number must be issued by Morningstar prior to return of
anyunit(s)underthiswarranty.RequiredRMAinformation:
(A) purchase location - business or company name - and date
(B) full model and serial numbers (SN is 8-digits on unit bar label)
(C)failurebehavior,includingLEDindications
(D)arrayconguration,panelPmax,Voc,Vmp,Isc,and
nominalbatteryvoltage-thesespecicationsareneededtoreceive
assistance.
(E)multi-meteravailable(foreldtroubleshooting)
Afterthedealeriscontacted,andisnotabletoassistwithwarranty
claim,contactMorningstarTechnicalSupportatsupport@
morningstarcorp.com. Please provide proof of date and place of
purchase,andalldetailslistedinprecedingparagraph.
R20-4/23
CERTIFICATIONS
RoHS
FOR CURRENT DETAILED CERTIFICATION LISTINGS, REFER
TO: https://www.morningstarcorp.com/support/library
Under, “Type”, choose, “Declaration of Conformity (DOC)”, to
view a list of product DOCs.
MeterbusTM
Morningstar Corporation
MODBUSTM and MODBUS TCP/IPTM are trademarks of
Modbus IDA.
©2023 Mornin
gst ar Corporation. All rights reserved.
MS-001170 v4