M20 Hardware Design
RI0
Idle or
talking
URC or
SMS Received
HIGH
LOW
120ms
Figure 40
: RI0 behaviour of URC or SMS received
3.14 Network status indication
The NETLIGHT signal can be used to drive a network status indication LED. The working state
of this pin is listed in Table 26.
Table 26: Working state of NETLIGHT
State
Module function
Off
The module is not running
64ms On/ 800ms Off
The module is not synchronized with
network
64ms On/ 2000ms Off
The module is synchronized with
network
64ms On/ 600ms Off
GPRS data transfer is ongoing.
A reference circuit is shown in Figure 41:
Module
300R
4.7K
47K
VBAT
NETLIGHT
Figure 41
: Reference circuit of NETLIGHT
M20_HD_V1.01
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Quectel