Do you want professional system monitoring and data logging? In that case KACO proLOG is the high-end solution for your PV system. It provides error messages via SMS fax or e-mail as well as remote monitoring web access and many other features. Up to 32 devices can be connected to KACO proLOG via an RS485 interface. 
Overview of KACO proLOG functions: 
proLOG data access via: blueplanet web Ethernet or Compact flash card. 
Number of Inverters that can be connected: 32 
Address range for each inverter: 1….32 
Data port for connecting inverter and sensors: B5485 
Analog ports for connecting sensors: 1 
Digital ports for connecting sensors: 1 
Alarm or S O ports: 1 
Display options 6 LEDs 
Memory: Compact Flash Card 
Data port for local analysis: Ethernet 
Data storage intervals: 5-60 Minutes 
Integrated transformer: Included 
KACO proLOG technical specifications 
Ambient: 32F-131F 
Storage and transportation: -5F-150F 
Current consumption: appx. 4W 
External power supply: 120 V 
Analog inputs (customizable): 0 VDC-10VDC/0mA-20mA (Max load: 40mA/3VDC)/PI 1000 resetance testing 
Digital inputs: Low=0VDC-7VDC/High=9VDC-24VDC 
Digital outputs: Optocoupler outpu(max load: 70VDC/50mA) 
Internal battery (for internal clock): Lithium Cell / Type Ll2032 
Enclosure: IP21/NEMA 2 (indoor enclosure):