Quectel EC21-A User Manual

LTE Standard Module Series
EC21_Series_Hardware_Design
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Table 20: Pin Definition of Network Connection Status/Activity Indicator
Pin Name
Pin
No.
I/O Description Comment
NET_MODE 5 DO
Indicate the module’s network
registration mode
1.8 V power domain.
Cannot be pulled up before startup.
If unused, keep it open.
NET_STATUS 6 DO
Indicate the module’s network
activity status
1.8 V power domain
If unused, keep it open.
Table 21: Working State of Network Connection Status/Activity Indicator
Pin Name Logic Level Changes Network Status
NET_MODE
Always High Registered on LTE network
Always Low Others
NET_STATUS
Flicker slowly (200 ms High/1800 ms Low) Network searching
Flicker slowly (1800 ms High/200 ms Low) Idle
Flicker quickly (125 ms High/125 ms Low) Data transfer is ongoing
Always High Voice calling
A reference circuit is shown in the following figure.
Figure 29: Reference Circuit of the Network Indicator

Quectel EC21-A Specifications

General

Brand	Quectel
Model	EC21-A
Category	Control Unit
Language	English