Read Can Bus Data of Danfoss Controller

One approach is to learn CAN and get all the stuff needed for CAN.

I've never done CAN, but all industrial protocols involve common factors.

You need
- PC software that can implement whatever control or monitoring you envision
- PC hardware interface for the specific digital communications protocol
- Cabling with appropriate connectors to connect from PC to whatever device
- A device with the complementary comm hardware and firmware, in this case CAN
(I've known people to connect cables only to discover that the RS-232 port has no Modbus functionality; sometimes comm options are not installed on the device in question)
- working knowledge of the comm protocol, in this case CAN
- working knowledge of the device and its communications, which means reading the manual to see how to get it do what you intend.

National Instruments (NI) sells PC software, Labview, that is widely used for control and monitoring projects. NI sells a wide variety of hardware for control and monitoring

A university has a tutorial on Labview's CAN demo here:
http://www.rpi.edu/dept/ecse/mps/NI_User_Manual.pdf

NI has a strong knowledge base on-line, for instance, a one page tech note on Maximum Cable Length for CAN bus:
http://digital.ni.com/public.nsf/allkb/D5DD09186EBBFA128625795A000FC025

Another approach is to use a protocol converter, from one industrial protocol (that you might already be familiar with) to another, say, Profibus to CAN, or Ethernet/IP to CAN. Since I don't dabble in CAN, I don't know who does that but Google will gladly track your efforts to discover who does.