If you take maglev train, you can only reach Longyang Road. Then you can change to Subway Line 2 to People's Square and then to Line 1 to Shanghai Train Station. Shanghai Long-distance Bus Temrinal is near beside the north square of the train station. There are buses to Zhangjiagang every 10-20 minutes. It may takes 2.5 hours from Shanghai to Zhangjiagang.