请问bq40z50如何验证紧急关断功能？

您好，需要将SHUTDN pin接入系统，按shutdown按钮才会进入emergency shutdown mode
8.3.5.3 Emergency Shutdown
For battery maintenance, the emergency shutdown feature enables a push button action connecting the
SHUTDN pin to shutdown an embedded battery pack system before removing the battery. A high-to-low
transition of the SHUTDN pin signals the bq40z50-R1 to turn off both CHG and DSG FETs, disconnecting the
power from the system to safely remove the battery pack. The CHG and DSG FETs can be turned on again by
another high-to-low transition detected by the SHUTDN pin or when a data flash configurable timeout is reached.
验证emergency shutdown mode还可以同在 ManufacturerAccess（）下指令实现。
b. Send a Manual FET Control (MFC) sequence to ManufacturerAccess().
When the gauge is in the EMERGENCY FET SHUTDOWN state, the OperationStatus()[EMSHUT] = 1.

您好，如果设置NR = 1，在配置中使用EMSHUT_EN时，可以将SHUTDN 用作紧急关机引脚。

你好，我在文档中有看见这部分介绍，但是我按照文档中的设置，然后按下shutdown键，上位机并没有断开连接的意思，没有起作用。我用示波器抓取这个脚的波形，只有每250ms的一次脉冲，并没有持续的高电平，怎么才可以按文档中的说  按下这个按键启动shutdown模式，还有什么地方需要注意的吗？

你好，我知道SYS PRES 就是 SHUTDN pi，NR也是设置的1，但是想问这样的配置下，shutdown 为什么在按键按下去没有启动呢？

您好, TRM 描述如下:
5.2.1 BATTERY PACK REMOVED Mode/System Present Detection
Pack removal and system present detection should be disabled for non-removable packs by setting the
DA Configuration[NR] bit.
If the [NR] bit is set, the PRES input is not monitored. If [NR] is set and [EMSHUT_EN] is cleared, the
PRES pin should be tied to VSS. If [NR] and [EMSHUT_EN] are set, then the PRES input must be
configured correctly for that function.
请确认 PRES pin接法，建议 PRES pin悬空试一下

你好，我测试该功能的时候 PRES pin已经悬空了，要不然不会出现上面示波器的波形