User's Manual
PCS3_HD_v01.000-03
Confidential / Preliminary
Page 25 of 101
2013-10-21
PCS3 Hardware Interface Description
3.3 Power-Up / Power-Down Scenarios
3.3
Power-Up / Power-Down Scenarios
In general, be sure not to turn on PCS3 while it is beyond the safety limits of voltage and tem-
perature stated in Section 6.1. PCS3 would immediately switch off after having started and de-
tected these inappropriate conditions. In extreme cases this can cause permanent damage to
the module.
3.3.1
Turn on PCS3
When the PCS3 module is in Power-down mode, it can be started to Normal mode by driving
the IGT (ignition) line to ground. it is recommended to use an open drain/collector driver to
avoid current flowing into this signal line. Pulling this signal low triggers a power-on sequence.
To turn on PCS3 IGT has to be kept active at least 100ms. After turning on PCS3 IGT should
be set inactive to prevent the module from turning on again after a shut down by AT command
or EMERG_OFF. For details on signal states during startup see also Section 3.3.2 and Section
3.10.6.
IGT
Power
supply
active
Module
Firmware start up, command interface initialization
Function
active
0ms ~28ms ~5s
BATT+
IGT
PWR_IND
>100ms
VEXT
EMERG_OFF
ASC0
CTS0
USB*
Initial state
Initial state
Undefined state
Intermediate state
Intermediate state
* USB interface may take up to 5s to reach its active state (typ. 4s)
Figure 4: Power-on with IGT
Note: After power up IGT should remain high. Also note that with a USB connection the USB
host may take more than 5 seconds to set up the virtual COM port connection.
After startup or mode change the following URCs sent to every port able to receive AT com-
mands indicating the module’s ready state:
•
"^SYSSTART" indicates that the module has entered Normal mode.
•
"^SYSSTART AIRPLANE MODE" indicates that the module has entered Airplane mode.
These URCs notify the external application that the first AT command can be sent to the mod-
ule. If these URCs are not used to detect then the only way of checking the module’s ready
state is polling. To do so, try to send characters (e.g. “at”) until the module is responding.