using ni 9401 with visa, rs232 connection

Hello all, 

I am using an ni 9401 Digital I/O module with an ni cDAQ-9178 Chassis. I would like to connect two mass flow controllers made by alicat to the 9401 module, and read and write to said controllers. The controllers use a serial rs232 connection, and I had vis built with the assistance of another community member that allowed me to communicate with them. I have made an adapter that connects the 2 9 pin cables to the 25 pin port on the 9401 module. I also know which specific pins are used for input and output to each controller. What would I need to do to control my controllers in this manner?

Any help is greatly appreciated

Thank you,

yp21