6i25 + 7i76 not reading custom inputs

I assigned tb6 inputs 7 and 8 as tool sync and tool strobe, and I'm getting a flatline false signal for both of them on the hal scope, show, meter etc. E-stop and limit switches are functioning fine in inputs 0-3 of tb6, so I don't know why I can't get anything on those pins. Before I figured out that I could type names in the pncconfig pins I had tried to read the 7i76 pins with the same result. I am getting the expected voltages on a meter to the tb6 pin screws, which go high at 4.76V. The only differences I know of between the inputs that work and those that don't are that the working ones were drop down selections in pncconfig and running on 24v field power, whereas the nonworking ones I renamed them from unused input, and they are 5V.

If you have 24V field power you cannot read 5V inputs, only 24V signals

Shouldn't I still be able to read the voltage on the hal-scope?

You can read TB6 pins 1 through 4 as analog values if you select sserial mode 1 or 2

I haven't figured out how to change modes. I just found a sainsmart 2 channel relay module in one of my boxes so I could use that unless there is an easier way?

There are a couple of ways of reading 5V signals on a 7I76 if you have 24V field I/O

1. If you are not using the encoder inputs, they can be use as three 5V inputs when set to TTL mode
2. You can cheat and read the inputs 0..3 as analog values and use the "comp" component to
set a threshold value and get a boolean output

you can enable the analog inputs (and MPG inputs) by adding a "sserial_port_0=2xxx" to the config string