What is a "dry contact input"?
Dry contact means no energy is supplied to the contacts (completely passive and isolated). In order for the DAQ to read it, it needs to have a defined voltage, Either a pull up to the positive supply (logic 1) or pull down resistors to the negative supply (logic 0) or an additional IO. Usually, DAQs have a reference voltage output, you can use that one, or alternately, an output line, set to a known logic level. Supply voltage is relative to the DAQ supply, either its ground or Vcc.
 As long as the cable between the alarm and IO board is relatively short, you should not have any problems.