I'm developing a control unit for ventilation systems. Beside switching those fans with a relay they are often controlled with a 0-10V analog signal. Now I found a product that uses a RJ45-plug to supply a 0-10V analog signal.
As the controller's going to have network features as well, chances are that a user will mix up the fan-dimming-RJ45 plug with an Ethernet plug.
So I wonder:
- might connecting this 0-10V output to a network harm a router/other network devices?
- isn't it generally bad practice in electronics to (ab)use a plug that belongs to a different standard for this purpose?
I'd like to support this interface only if it is safe if accidentally connected to a network.
The 4 lines involved are:
- 10V power supply for internal circuit
- 0-10V dimming signal
- tachometer signal
Remaining lines are NC.