起初连接正常，通讯数据均可互传，但是最近上位机老报：读请求响应失败错误；硬件诊断中的错误提示信息如下：
Event 1 of 121: Event ID 16# F9C1:0277
No entry in text database. Hexadecimal values will be displayed.
Event ID: 16# F9C1
Detail event: 16# 0277
Additional info 4 / 5: 16# 02 00
Additional info1 / 2 / 3: 16# 0000 0101 6400
External error, Incoming event
03:07:37.125 AM 01/02/1994


Event 2 of 121: Event ID 16# F9C1:0278
No entry in text database. Hexadecimal values will be displayed.
Event ID: 16# F9C1
Detail event: 16# 0278
Additional info 4 / 5: 16# 02 00
Additional info1 / 2 / 3: 16# 0000 0101 0000
External error, Incoming event
02:59:06.386 AM 01/02/1994

求各位大侠帮忙分析下，问题出在哪里，小弟在这先谢了
问题补充：在出现上述问题时，step 7软件通过CP343-1的以太网监控也时常连接不上，但是模块上并未有报错信息，SF，BF均正常。