What is the PLC doing - if the signal is 'mission critical' to fire safety,then it is as important as the fire detector and alarm wiring (and then so to are the failure modes of the PLC and the supply to it.). If it is just some house keeping signal, that does not affect the response to a fire, then it isn't.

Mike.

It is an industrial PRR. To be more precise the fire interface is connected to our ventilation control panel. Once the fire alarm occurs we need our ventilation fans to turn off basically. 

We have 2 dedicated terminals on a circuit to trigger one of the digital inputs on PLC so it can shut the power supply off the fans.

The whole Fire Alarm system is make by 3rd party company and ventilation control panel by us.

What missing is the cable between fire interface NO/NC contact and our vent panel - PLC. Can standard H07 be used or it needs to be FP one?

If the fans turning off are critical to the fire response (and the way you word it they are " Once the fire alarm occurs we need our ventilation fans to turn off " ) then it needs the same protection as you would afford to similar measures that prevent the spread of fire , like wiring to a door closer or window shutters and so on - it is all part of the fire system. 
The choice of cable is one thing, and may be relaxed if routed in a way that affords it some fire protection but I'm a bit worried that the whole fan control thing may be a bit odd as well.  I think I'd have preferred a contactor that cut the power to the fans regardless of the state of the PLC software personally..

I presume this set up has been designed and approved by someone who knows what they are doing  ? If you can,  ask them about the strategy to prevent the spread of fire ?
Mike

If the fans turning off are critical to the fire response (and the way you word it they are " Once the fire alarm occurs we need our ventilation fans to turn off " ) then it needs the same protection as you would afford to similar measures that prevent the spread of fire , like wiring to a door closer or window shutters and so on - it is all part of the fire system. 
The choice of cable is one thing, and may be relaxed if routed in a way that affords it some fire protection but I'm a bit worried that the whole fan control thing may be a bit odd as well.  I think I'd have preferred a contactor that cut the power to the fans regardless of the state of the PLC software personally..

I presume this set up has been designed and approved by someone who knows what they are doing  ? If you can,  ask them about the strategy to prevent the spread of fire ?
Mike