On our company we do black box tests for embedded systems, but we don't use any framework. What we do for now is testing the embedded software by accessing to the registers of the device through ModBus. We use Python to do it, and as you can imagine, there is a lot of pain. Manually writing the assertions... There are many issues to setup the device on a default state so one test doesn't interfere to another, and so on.
Is there any open source / free black box testing framework using ModBus?