How to check the night traffic balance with 3G Unicom card?

Spare-time traffic or night residual traffic is generally inquired by 100 10 or customer service in the business hall. However, some provinces can also make inquiries through SMS. For example, the 3G users of Guangdong Unicom have superimposed the 3G free-to-play time traffic packet. You can query the remaining traffic of the free-to-play traffic packet by sending a short message CXSYW to 100 10.