OH2 on Synology + MySensors serial GW

I am trying to build my HomeAutomation central using OH2 and custom MySensors gateway running on Synology DS111.
Instalation of OH2 was easy and works fine. Serial Gateway works fine on its own too. Problem is to configure communication between OH2 and gateway. Serial Binding is installed throu Control Panel.
Demo.things contains:

Bridge mysensors:bridge-ser:gateway [ serialPort="/dev/pts/2", sendDelay=200 ] {
	humidity 		hum01 	[ nodeId=170, childId=170 ]
	temperature		temp01 	[ nodeId=170, childId=170 ]

and demo.items contains:

  Number hum01 	  "Humidity [%s %%Rh]" { channel="mysensors:humidity:gateway:hum01:hum" }
  Number temp01	  "Temperature" { channel="mysensors:temperature:gateway:temp01:temp" }

I dont know how to figure out for example SerialPort path in *.things file.
Would someone be so kind and try to help me to figure out how to make the system work?