Connection slave device is unsuccessful
1. Follow the steps of the operation step by step, see page 22 of the manual;
2. Write "host parameters" before "write slave parameters".
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Using WT01 transparent transmission, data points are not online
1. Whether the S280 host and WT01 match successfully(see the indicator light, the 433 lights of the S280 are flashing, if it flashes, it proves that the match is successful)
2. Whether the setting of the S280 host sets the working mode to transparent transmission;
3. Whether the RS485 parameter of the slave is the same as that of WT01 (the parameters of WT01 are fixed as: baud rate 9600, data bit 8, no test, stop bit 1);
4. Whether the address setting of the slave is correct;
5. The parameter setting of the data point of the slave is incorrect (register address, function code, etc.)

Send SMS instructions to the device and the device does not response
1.Look at the flashing of the signal light to determine whether the device has registered the signal;
2. Is there any error in the device password, default 1234, if it has been changed in the configuration software, the new password should be used;
3. Is there any error in the short message instruction? Notice that there is no "+", and "#" is under the English input method;
4. Whether the mobile phone card in the device has the SMS function enabled;
5. If you use SMS APP to send short messages to the device without reply, please check whether the mobile phone has the right to send short messages and make phone calls to SMS APP.

The device has triggered an alarm but does not send an alarm message/call
1. The device is not "armed". Please use the SMS command or the configuration software to "arm".
2, the battery voltage is too low, can not send text messages, please connect the external power supply to charge the device;
3. The format of the telephone number is incorrect, and the country code should be added, for example, China is 0086.
4. The GSM signal is too low;
5. The SIM card in the device is in arrears.