Micha Solar
MSRx Charge Controller
User Operation Manual
Page 32 of 46
Document: 802440-30.doc
Date: December 2020
www.micha.co.uk
6. MSRx Expansion Port Modules
6.1. 4-Channel Alarm Relay Din Rail Module
The 4-Channel Alarm Relay Din Rail Module connects to the MSRx Control PCB Assembly Expansion
Port to provide four Alarm Relay Outputs (Volt-free change-over contacts).
6.2. 4-20mA Transducer Type A Din Rail Module
The 4-20mA Transducer Type A Din Rail Module connects to the MSRx Control PCB Assembly
Expansion Port to provide one 4-20mA output signal (Type A requires an external power source for the 4-
20mA signal).
6.3. 4-20mA Transducer Type B Din Rail Module
The 4-20mA Transducer Type B Din Rail Module connects to the MSRx Control PCB Assembly
Expansion Port to provide one 4-20mA output signal (Type B uses an internal dc-dc converter to provide
power for the 4-20mA signal).
6.4. Analogue Input Din Rail Module
The Analogue Input Din Rail Module connects to the MSRx Control PCB Assembly Expansion Port to
enable the controller to measure an Auxiliary Voltage, an Auxiliary Temperature, and Solar Irradiation
(using a Solar Pyranometer).
6.5. 8-Channel Digital Input DIN Rail Module
The 8-Channel Digital Input DIN Rail Module connects to the MSRx Control PCB Assembly Expansion
Port to provide 8 x Volt-Free Digital Inputs. The Digital Inputs can be programmed to activate an alarm
when the input becomes active. The alarm is seen on the LCD display and may activate an Alarm Relay
if required.
6.6. USB/RS232 Com Port & Data Logger or USB/RS485 Com Port & Data Logger
The USB/RS232(or RS485) Com Port & Data Logger Module connects to the MSRx Control PCB
Assembly Expansion Port to provide the user with a Com Port which is isolated electrically from the
MSRx Charge Controller. Data Logging records operation and status of the charge controller in non-
volatile memory.
MSRComms Software (available free from Micha Design) may be used to download the Data Log to a
PC.
6.7. MSRx RTD Interface Module
The MSRx RTD Interface is designed to allow a PT100 Resistor Temperature Detector (RTD) to be used
with the MSRx Charge Controller. The Interface can be supplied in DIN rail or pillar mounting and
connects to the MSRx Expansion Port with a ribbon cable supplied.