Mixed IO on 7i69

So my laser requires a massive amount of I/O to control it and it is at a 15v logic level. My solution is to use a 7i69 and control two Opto22 Quad racks with 24 IOs per rack. It is something like 30 bits of output and about 6 inputs. I want to keep this all separate from the servo control chain which is 24v so the racks work well for this.

According to the manual and the linuxcnc sserial page and it says I can use Mode 0 to do bidirectional on any pin. So, the first question, will this mode work with standard idc5q input modules? Second, it looks like pmcconf will only let me set up one 50 pin header for in and one for out, or did I miss something?

So basically I need one header all output, no problem. The second header I will need another 8 outs and probably configure the rest as inputs. Is this possible?

Its certainly possible hardware wise (normal input modules are active low so work fine with the 7I69)
but pncconf may not know how so you will probably have to wire (in HAL) the inputs and outputs
on the shared I/O connector.

The way the physical I/O pins work on the 7I69 is that they are open drain and bidirectional
that is, they can be pullled down either by asserting the 7I69 output for that pin or by an
external OPTO input device pulling the 7I69 input to ground. Note that when bidirectional pins are used as
inputs, the output HAL pin for those signals must be false '0'.