Hello i Have a dahua Video Dorbell and bought a second VTH Monitor 
	But the monitor has a newer FW 4.0 with SIP 
	and my first indor Monitor has a 3.2 Firmware without sip 
	I get an error if I install the 3.2 FW on the newer Monitor  
	The new VTH Monitor is vth1550ch-s2 (4.0FW) 
	The old is vth1510ch (3.2FW)  
	can someone help me?