The CAN bus is a simplistic, cheap, and robust interface that’s widely used for communications between microcontrollers but is a viable and cost-effective communications network for systems that are physically wired together. Vector Informatik GmbH has long dominated the space of CAN bus development/analysis tools, but the hardware and software offerings they provide are extremely pricey. This leads to organizations fighting over these tools, because they cannot justify the cost involved to allow all developers and testers to have the setup they require to get their work done.
In this post, I will be presenting some alternatives to the Vector suite that likely provide all of the necessary capabilities your teams require, but at a fraction of the price.
CANCaseXL – Vector Informatik
To get started, you need a CAN interface that you can hook up to your development/testing workstation. The Vector options these days are limited and pricey, and you will end up spending about $1000 to get a Vector CANCase, which supports up to 2 CAN busses. You’ll have to pay a bit more to get the transceivers that work with the low and/or high speed CAN busses. Low-speed is generally 100-125 kbit/sec, and high-speed is usually 250-500 kbit/sec, but up to 1 Mbit/sec rate is achievable as well. A lower bus speed allows for bus lengths of up to 500m, and also allows for longer taps off of the bus. Higher rates mean more bandwidth and faster interaction, which is usually used for smaller time-critical networks.
CANUSB/CAN232 – LAWICEL
Fairly low price options are available from LAWICEL, based out of Sweden. Their CAN232 (serial-port to CAN) sells for $109, and the CANUSB (USB to CAN) is slightly more at $140, but well worth the extra cost if (like most developers) you no longer have a serial port on your laptop or even desktop machine.
The CANUSB can utilize of virtual COM port driver, so that it appears to your system as a standard serial port, which can make it trivial to write your own tools or test rigs. If you need higher bandwidth for high bus-loads, a direct USB driver is available as well. USB drivers for CANUSB are available for Windows, OSX and Linux, although the bus monitor utilities available from LAWICEL are Windows-only.
ValueCAN – Intrepid Control Systems
Intrepid Control Systems offers the ValueCAN3 at $300. Rumor has it that the CANUSB/232 from LAWICEL falls short on higher bus rates, or even highly loaded busses at lower rates. The ValueCAN can keep up with a fully loaded 1 Mbit/sec bus. The ValueCAN achieves this in part by utilizing a true USB interface, unlike the CANUSB, which uses an off-board serial-to-USB converter chip from FTDI.
The ValueCAN3 comes with a limited trial license for its Vehicle Spy software, but a full license for the basic version is $1000 per seat. This is still significantly cheaper that what you would pay Vector! Another pitfall of the ValueCAN is that the software and driver are only available for the Windows platform.
PCAN-USB – PEAK-System
The PCAN-USB from PEAK System has fit the bill myself and many others. You can buy it in the U.S. for $255, and you can upgrade to the 500V isolated version for $70 more so that you don’t let the smoke out of your laptop/PC! The PCAN-USB comes with a free utility, PCAN-VIEW, for sniffing the CAN bus. They do offer higher end software, with various options as well, but they are fairly costly.
Although the PCAN-USB supplied PCAN-VIEW and other software programs are Windows-only, uvsoftware has developed free device drivers for Linux and OSX as well. To top it off, uvsoftware also has a slew of different free and multi-platform software packages, and the source code is also available for the super techies who want to dig in and write their own kick-ass test rigs!