1、Machine room telephone line checking：
1.1. If there is a telephone set in the machine room, find the two signal lines of the original telephone set in the machine room (the back of the telephone set in the machine room is usually marked with L and R), disconnect the two lines L and R, and conduct positive and negative measurement on the two signal lines with the voltage range of the multimeter to see if they are live;
1.11 normal if there is no electricity;
1.12 in case of live electricity, check the two accompanying cables (directly to the bottom of the car) : check whether there are multiple connections in the middle or other lines in parallel (drawings can be checked), disconnect the accompanying cable power supply after check (until the two lines are completely independent), and measure without voltage before proceeding to the next step;
2、Cage interphone line checking：
Let the maintenance cooperation come to the car, open the car key panel, remove the original car phone two signal lines, with the multimeter for voltage, short circuit, open circuit test.
2.1 voltage measurement: use the voltage level of the multimeter to measure whether the two wires are live or not. If they are normally live, it is necessary to check the accompanying cable lines (the same method as 1.12).
2.2 short-circuit measurement: inform the machine room staff to put the two signal lines of the machine room telephone together. At this time, use the multimeter resistance to measure whether the two cables of the car communicator are on or not. Normally, all the cables should be on. If not, the accompanying cable is broken, or there is a connecting wire in the middle;
2.3 open circuit measurement: allow the machine room staff to disconnect two signal lines, and use the multimeter resistance to measure in the cage, which should be completely disconnected normally (the resistance value is infinite). If it is not completely disconnected, there will be short-circuit in the two boxes of signal lines of the accompanying cables. Remark: all measurements are subject to 2~3 times.
After the above test is correct, it can be directly connected to the yellow and green line of the car communicator of spritong brand.
3、Car call button line check：
3.1 call button voltage measurement: test the two lines of the call button with the voltage level of a multimeter, which should not be electrified normally. If it is live, a relay should be installed (see the failure countermeasures table for installation method).
3.2 call button measurement: when the call button is pressed down, the multi-meter resistance is used to measure that the two lines of the call button are on. If the call button is not on, the button may be defective and needs to be replaced.
After the above check is correct, connect the call button wire to the switch contact of the car communicator.
Note: when searching the accompanying cable of the elevator, it can be found according to the Numbers on the two signal lines of the machine room and the car box, saving the time of checking the cable.