I am using the FR-15 for digital inputs but I need to detect a 24V signal. the Logic I have is either 24V or an open circuit.
I see there is an option to use a 10K pull-down resistor and jumper, is the 10k pull-down resistor built in and enabled with the Jumper?
I had planned to use a resistor divider to get the 24V signal down to 5V to use with the FR-15 but the 10k resistor will affect my choice of resistor divider, are there any other considerations on the FR-15 that may affect this circuit such as input impedance on the ADC inputs or device used for digital I/O?
Can you confirm this is the product you are using?
If so are you using this input board:
The A/D inputs on these devices are only rated for 5VDC. You will need to externally condition that 24V signal to a dry contact closure or a 0-5VDC signal. This could be done using a simple external 24V coil relay.
Yes that is the board I am using. I was not planning on using the terminal block adapter, I have another terminal block I will be connecting to with a cable, but if that is recommended I can use the same terminal block adapter.
I actually planned on using two of the FR-15 boards connected to the same device so I can monitor from two different controllers via RS485